What is a System:- Characteristics of a system:-

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1 Unit 1 st :- What is a System:- A system is an odely gouping of intedependent components linked togethe accoding to a plan to achieve a specific objective. The study of system concepts has thee basic implications: 1. A system must be designed to achieve a pedetemined objective. 2. Inteelationships and intedependence must exist among the components. 3. The objectives of the oganization as a whole have a highe pioity than the objectives of its subsystems. Chaacteistics of a system:- 1. Oganization: It implies stuctue and ode. It is the aangement of components that helps to achieve objectives. 2. Inteaction: It efes to the manne in which each component functions with othe components of the system. 3. Intedependence: It means that pats of the oganization o compute system depend on one anothe. They ae coodinated and linked togethe accoding to a plan. One subsystem depends on the output of anothe subsystem fo pope functioning. 4. Integation: It efes to the holism of systems. It is concened with how a system is tied togethe. 5. Cental Objective: A system should have a cental objective. Objectives may be eal o stated. Although a

2 stated objective may be the eal objective, it is not uncommon fo an oganization to state one objective and opeate to achieve anothe. The impotant point is that uses must know the cental objective of a compute application ealy in the analysis fo a successful design and convesion. Elements of a System:- 1. Outputs and inputs: A majo objective of a system is to poduce an output that has value to its use. In ode to get a good output, inputs to system must be appopiate. It is impotant to point out hee that detemining the output is a fist step in specifying the natue, amount and egulaity of the input needed to opeate a system. 2. Pocessos: It is the element of a system that involves the actual tansfomation of input into output. It is the opeational component of a system. Pocessos may modify the input totally o 2 patially, depending on the specifications of the output. In some cases, input is also modified to enable the pocesso to handle the tansfomation. 3. Contol: The contol elements guide the system. It is the decision-making subsystem that contols the patten of activities govening input, pocessing, and output. 4. Feedback: Feedback measues output against a standad in some fom of cybenetic pocedue that includes communication and contol. Feedback may be positive o negative, outine o infomational. Positive feedback einfoces the pefomance of the system. It is outine in natue. Negative feedback geneally povides the contolle with infomation fo action.

3 5. Envionment: The envionment is the supa-system within which an oganization opeates. It is the souce of extenal elements that impinge on the system. In fact, it often detemines how a system must function. 6. Boundaies and Intefaces: A system should be defined by its boundaies- the limits that identify its components, pocesses, and inteelationships when it intefaces with anothe system. Types of System:- 1. Physical o Abstact Systems: Physical systems ae tangible entities that may be static o dynamic in opeation. 2. Abstact systems ae conceptual o nonphysical entities. They may be fomulas of elationships among sets of vaiables o models the abstact conceptualization of physical situations Open o Closed Systems: An open system has many intefaces with its envionment. It pemits inteaction acoss its boundaies; it eceives inputs fom and delives outputs to the outside. A closed system is isolated fom envionment influences. SDLC Oveview SDLC, Softwae Development Life Cycle is a pocess used by softwae industy to design, develop and test high quality softwaes. The SDLC aims to poduce a high quality softwae

4 that meets o exceeds custome expectations, eaches completion within times and cost estimates. SDLC is the aconym of Softwae Development Life Cycle. It is also called as Softwae development pocess. The softwae development life cycle (SDLC) is a famewok defining tasks pefomed at each step in the softwae development pocess. ISO/IEC is an intenational standad fo softwae life-cycle pocesses. It aims to be the standad that defines all the tasks equied fo developing and maintaining softwae. What is SDLC? SDLC is a pocess followed fo a softwae poject, within a softwae oganization. It consists of a detailed plan descibing how to develop, maintain, eplace and alte o enhance specific softwae. The life cycle defines a methodology fo impoving the quality of softwae and the oveall development pocess. The following figue is a gaphical epesentation of the vaious stages of a typical SDLC.

5 A typical Softwae Development life cycle consists of the following stages: Stage 1: Planning and Requiement Analysis Requiement analysis is the most impotant and fundamental stage in SDLC. It is pefomed by the senio membes of the team with inputs fom the custome, the sales depatment, maket suveys and domain expets in the industy. This infomation is then used to plan the basic poject appoach and to conduct poduct feasibility study in the economical, opeational, and technical aeas. Planning fo the quality assuance equiements and identification of the isks associated with the poject is also done in the planning stage. The outcome of the technical feasibility study is to define the vaious technical appoaches that can be followed to implement the poject successfully with minimum isks. Stage 2: Defining Requiements Once the equiement analysis is done the next step is to clealy define and document the poduct equiements and get them appoved fom

6 the custome o the maket analysts. This is done though.srs.. Softwae Requiement Specification document which consists of all the poduct equiements to be designed and developed duing the poject life cycle. Stage 3: Designing the poduct achitectue SRS is the efeence fo poduct achitects to come out with the best achitectue fo the poduct to be developed. Based on the equiements specified in SRS, usually moe than one design appoach fo the poduct achitectue is poposed and documented in a DDS - Design Document Specification. This DDS is eviewed by all the impotant stakeholdes and based on vaious paametes as isk assessment, poduct obustness, design modulaity, budget and time constaints, the best design appoach is selected fo the poduct. A design appoach clealy defines all the achitectual modules of the poduct along with its communication and data flow epesentation with the extenal and thid paty modules (if any). The intenal design of all the modules of the poposed achitectue should be clealy defined with the minutest of the details in DDS. Stage 4: Building o Developing the Poduct In this stage of SDLC the actual development stats and the poduct is built. The pogamming code is geneated as pe DDS duing this stage. If the design is pefomed in a detailed and oganized manne, code geneation can be accomplished without much hassle. Developes have to follow the coding guidelines defined by thei oganization and pogamming tools like compiles, intepetes, debugges etc ae used to geneate the code. Diffeent high level pogamming languages such as C, C++, Pascal, Java, and PHP ae used fo coding. The pogamming language is chosen with espect to the type of softwae being developed. Stage 5: Testing the Poduct This stage is usually a subset of all the stages as in the moden SDLC models, the testing activities ae mostly involved in all the stages of

7 SDLC. Howeve this stage efes to the testing only stage of the poduct whee poducts defects ae epoted, tacked, fixed and etested, until the poduct eaches the quality standads defined in the SRS. Stage 6: Deployment in the Maket and Maintenance Once the poduct is tested and eady to be deployed it is eleased fomally in the appopiate maket. Sometime poduct deployment happens in stages as pe the oganizations. business stategy. The poduct may fist be eleased in a limited segment and tested in the eal business envionment (UAT- Use acceptance testing). Then based on the feedback, the poduct may be eleased as it is o with suggested enhancements in the tageting maket segment. Afte the poduct is eleased in the maket, its maintenance is done fo the existing custome base. SDLC Models:- Thee ae vaious softwae development life cycle models defined and designed which ae followed duing softwae development pocess. These models ae also efeed as "Softwae Development Pocess Models". Each pocess model follows a Seies of steps unique to its type, in ode to ensue success in pocess of softwae development. Following ae the most impotant and popula SDLC models followed in the industy: Watefall Model Iteative Model Spial Model V-Model Big Bang Model The othe elated methodologies ae Agile Model, RAD Model, Rapid Application Development and Pototyping Models. Watefall Model

8 Watefall Model design Watefall appoach was fist SDLC Model to be used widely in Softwae Engineeing to ensue success of the poject. In "The Watefall" appoach, the whole pocess of softwae development is divided into sepaate phases. In Watefall model, typically, the outcome of one phase acts as the input fo the next phase sequentially. Following is a diagammatic epesentation of diffeent phases of watefall model. The sequential phases in Watefall model ae: Requiement Gatheing and analysis: All possible equiements of the system to be developed ae captued in this phase and documented in a equiement specification doc. System Design: The equiement specifications fom fist phase ae studied in this phase and system design is pepaed. System Design helps in specifying hadwae and system equiements and also helps in defining oveall system achitectue.

9 Implementation: With inputs fom system design, the system is fist developed in small pogams called units, which ae integated in the next phase. Each unit is developed and tested fo its functionality which is efeed to as Unit Testing. Integation and Testing: All the units developed in the implementation phase ae integated into a system afte testing of each unit. Post integation the entie system is tested fo any faults and failues. Deployment of system: Once the functional and non functional testing is done, the poduct is deployed in the custome envionment o eleased into the maket. Maintenance: Thee ae some issues which come up in the client envionment. To fix those issues patches ae eleased. Also to enhance the poduct some bette vesions ae eleased. Maintenance is done to delive these changes in the custome envionment. All these phases ae cascaded to each othe in which pogess is seen as flowing steadily downwads (like a watefall) though the phases. The next phase is stated only afte the defined set of goals ae achieved fo pevious phase and it is signed off, so the name "Watefall Model". In this model phases do not ovelap. Watefall Model Application Evey softwae developed is diffeent and equies a suitable SDLC appoach to be followed based on the intenal and extenal factos. Some situations whee the use of Watefall model is most appopiate ae: Requiements ae vey well documented, clea and fixed. Poduct definition is stable. Technology is undestood and is not dynamic. Thee ae no ambiguous equiements.

10 Ample esouces with equied expetise ae available to suppot the poduct. The poject is shot. The spial model combines the idea of iteative development with the systematic, contolled aspects of the watefall model. Spial model is a combination of iteative development pocess model and sequential linea development model i.e. watefall model with vey high emphasis on isk analysis. It allows fo incemental eleases of the poduct, o incemental efinement though each iteation aound the spial. Spial Model design The spial model has fou phases. A softwae poject epeatedly passes though these phases in iteations called Spials. Identification:This phase stats with gatheing the business equiements in the baseline spial. In the subsequent spials as the poduct matues, identification of system equiements, subsystem equiements and unit equiements ae all done in this phase. This also includes undestanding the system equiements by continuous communication between the custome and the system analyst. At the end of the spial the poduct is deployed in the identified maket. Design:Design phase stats with the conceptual design in the baseline spial and involves achitectual design, logical design of modules, physical poduct design and final design in the subsequent spials. Constuct o Build:Constuct phase efes to poduction of the actual softwae poduct at evey spial. In the baseline spial when the poduct is just thought of and

11 the design is being developed a POC (Poof of Concept) is developed in this phase to get custome feedback. Then in the subsequent spials with highe claity on equiements and design details a woking model of the softwae called build is poduced with a vesion numbe. These builds ae sent to custome fo feedback. Evaluation and Risk Analysis:Risk Analysis includes identifying, estimating, and monitoing technical feasibility and management isks, such as schedule slippage and cost oveun. Afte testing the build, at the end of fist iteation, the custome evaluates the softwae and povides feedback. Following is a diagammatic epesentation of spial model listing the activities in each phase: Based on the custome evaluation, softwae development pocess entes into the next iteation and subsequently follows the linea appoach to implement the feedback suggested by

12 the custome. The pocess of iteations along the spial continues thoughout the life of the softwae. DOCUMENTATION:- Documentation is a set of documents povided on pape, o online, o on digital o analog media, such as audio tape o CDs. Examples ae use guides, white papes, on-line help, quick-efeence guides. It is becoming less common to see pape (had-copy) documentation. Documentation is distibuted via websites, softwae poducts, and othe on-line applications. Pofessionals educated in this field ae temed documentalists. This field changed its name to infomation science in 1968, but some uses of the tem documentation still exists and thee have been effots to eintoduce the tem documentation as a field of study. Pinciples fo poducing documentation] While associated ISO standads ae not easily available publicly, a guide fom othe souces fo this topic may seve the pupose. David Bege has povided seveal pinciples of document witing, egading the tems used, pocedue numbeing and even lengths of sentences, etc. ] Pocedues and techniques[ The pocedues of documentation vay fom one secto, o one type, to anothe. In geneal, these may involve document dafting, fomatting, submitting, eviewing, appoving, distibuting, eposting and tacking, etc., and ae convened by associated SOPs in a egulatoy industy. Documentation should be easy to ead and undestand. If it's too long and too wody, it may be misundestood o ignoed. Clea, Shot, Familia wods should be used to a maximum of 15 wods to a sentence. Only gende hype neutal wod should be used and cultual biases should be avoided. Pocedues should be numbeed when they ae to be pefomed. Poducing documentation] Technical wites and copoate communicatos ae pofessionals whose field and wok is documentation. Ideally, technical wites have a backgound in both the subject matte and also in witing and managing content (infomation achitectue). Technical wites moe commonly collaboate with subject matte expets (SMEs), such as enginees, medical pofessionals, o othe types of clients to define and then ceate

13 content (documentation) that meets the use's needs. Copoate communications includes othe types of witten documentation that is equied fo most companies. Specializing documentation:- Maketing Communications (MaCom): MaCom wites endeavo to convey the company's value poposition though a vaiety of pint, electonic, and social media. This aea of copoate witing is often engaged in esponding to poposals. Technical Communication (TechCom): Technical wites document a company's poject o sevice. Technical publication include use guides, installation manuals, and toubleshooting/epai/eplace pocedues. Legal Witing: This type of documentation is often pepaed by attoneys o paalegals who could be in pivate pactice o etained as copoate council. Compliance documentation: This type of documentation codifies Standad Opeating Pocedues (SOPs), fo any egulatoy compliance needs, as fo safety appoval, taxation, financing, technical appoval, etc. Tools fo documenting softwae[ Thee ae many types of softwae and applications used to ceate documentation. SOFTWARE DOCUMENTATION FOLDER (SDF) A common type of softwae document witten by softwae enginees in the simulation industy is the SDF. When developing softwae fo a simulato, which can ange fom embedded avionics devices to 3D teain databases by way of full motion contol systems, the enginee keeps a notebook detailing the development "the build" of the poject o module. The document can be a wiki page, MS wod document o othe envionment. They should contain a equiements section, an inteface section to detail the communication inteface of the softwae. Often a notes section is used to detail the poof of concept, and then tack eos and enhancements. Finally, a testing section to document how the softwae was tested. This documents confomance to the client's equiements. The esult is a detailed desciption of how the softwae is designed, how to build and install the softwae on the taget device, and any known defects and wok-aounds. This build document enables futue developes and maintaines to come up to speed on the softwae in a timely manne, and also povides a oadmap to modifying code o seaching fo bugs.

14 new develope might be confused about which kinds of documentation ae impotant, because we often use the vey geneal tem documentation athe than specifying the type. Hee's a look at some of the types of documentation out thee. Code comments When documentation is mentioned amongst developes, comments inseted diectly into the souce code ae pobably the most common undestanding. This is especially tue fo ecent gaduates o newe pogammes who encounteed it in school, but neve leaned about moe igoous foms of documentation. Comments have lost a lot of thei utility ove the yeas. Between the development of systems allowing longe, moe desciptive vaiable names and development platfoms and systems that allow fo othe kinds of documentation, comments no longe seve as the de facto documentation solution. That said, code comments still have value. Code comments should not be used to eplace desciptive vaiable names, though they ae excellent fo explaining the logic undelying a piece of code not necessaily the how of a code block but the why. Fo example, a useful comment might be, "Spec says that a name must be thee chaactes long and have only lettes" to explain a piece of validation code. Comments become moe useful when they diectly efe to the specification, a bug, o othe extenal documentation in an easy-toefeence way. "Fix fo bug #598" o "Refe to change equest A991" can go a long way in helping futue maintaines undestand the thinking behind an othewise incompehensible piece of code. Witing useful comments along these lines should become a habit if it isn't one aleady. "Self-documenting" code Thanks to systems that allow vaiable, class, and function names to be longe than they used to be, it is much easie to wite "self-documenting" code; that is to say, the names of things convey thei meaning without the need fo inline comments. Fo example, a function such as "pfltocnsl" does not let the potential use know what it does as well as "Pint FloatToConsole." Like using inline comments wisely, this should become a standad pactice fo developes. Geneated API-style documentation

15 Some languages allow you to embed detailed documentation within the souce code in a fomat (typically XML) that automated tools can use to geneate packaged help. Some systems (like Visual Studio) can pick it up and use it in othe ways too. This can be a eally useful, but it is a lot of wok to do something useful. Bug tacke, task list, o poject management system Thee has been an explosion in tools that allow teams to ente bugs, tasks, to-do lists, and so on. The tools allow items to be tacked vey ganulaly, and fo the use to assign gobs of metadata to any given item. With this metadata, manages can do things like make gaphs, chats, and epots showing a ton of diffeent stats, like aveage bug esolution time o the numbe of featues implemented pe develope. Some of these systems can tie into you souce code system, so that you can easily view code check-ins in the context of the tasks they addessed (this is a vey handy featue). While the stats that can be pulled ae often of dubious elevance towads evaluating quality o poductivity, these systems have lots of value. Being able to apidly find and mine common bugs, change equests, and so on is a big help. It's also nice to not have to wade though endless piles of sepaate pieces of pape, s, o files nt TYPES OF INFORMATION SYSTEM:- Infomation systems diffe in thei business needs and the infomation vaies depending upon diffeent levels in oganization. infomation system can be boadly categoized into following : Tansaction pocessing system

16 Management Infomation System Decision suppot system The infomation needs ae diffeent at diffeent oganizational levels. Accodingly the infomation can be categoized into following: Stategic infomation Manageial infomation Opeational infomation. Tansaction Pocessing Systems 1. It pocesses business tansaction of the oganization. Tansaction can be any activity of the oganization. Fo example, take a ailway esevation system. Booking, canceling, etc ae all tansactions. Any quey made to it is a tansaction. 2. This povides high speed and accuate pocessing of ecod keeping of basic opeational pocesses and include calculation, stoage and etieval. 3. Tansaction pocessing systems povide speed and accuacy, and can be pogammed to follow outines functions of the oganization. Management Infomation Systems 1. It assist lowe management in poblem solving and making decisions. They use the esults of tansaction pocessing and some othe infomation also. 2. An impotant element of MIS is database.a database is a nonedundant collection of inteelated data items that can be pocessed though application pogams and available to many uses. Decision Suppot Systems 1. These systems assist highe management to make long tem decisions. These type of systems handle unstuctued o semi stuctued decisions. A decision is consideed unstuctued if thee ae no clea pocedues fo making the decision and if not all the factos to be consideed in the decision can be eadily identified in advance. 2. A decision suppot system must vey flexible. thee weeks making a change that eveyone seems to hate. UML UML is a special file fomat design fo documenting applications. UML can be consumed by a vaiety of tools to poduce documents, database

17 diagams, pocess flowchats, and moe. Even bette, some tools can take UML and stub out applications and databases based upon it. UML is paticulaly pevalent in the Java ecosystem, thanks to the Rational Suite of tools that IBM owns. UML seems to be consideed an entepise development tool, due to the leaning cuve and cost of the tools associated with it. Ad-hoc documents This style of documentation is sadly too pevalent. With ad-hoc documentation, you usually lack vesion contol. It's also difficult to seach and, wost of all, you tend to get multiple copies of the documents with diffeences floating all ove the place. Unit 2:- Systems planning to develop a schedule, esouce plan, and budget fo poject activities to ensue poject success Systems planning to develop a schedule, esouce plan, and budget fo poject activities to ensue poject success Top Ten Poject Risk Factos (CACM, Nov. 1998)

18 Poject management The task of planning and contolling IS poject activities 1. Select team membes 2. Assign team membes to pojects 3. Task time estimation 4. Task scheduling 5. Poject monitoing 6. Activities escheduling Skills: 1. Seek a balance between woking on tasks and maintaining elationships within the team. 2. Set easonable poductivity goals fo tangible outputs and pocess activities. 3. Motivate team membes though paticipative management. Requiements analysis to undestand and discove business needs and systems equiements by gatheing facts on: 1. Uses view, 2. Existing witten infomation such as mission statements, policies, epots, and documentation, 3. Data: what, when, how, and by whom the data ae collected, tansfomed, and stoed; ules govening data handling; key events affecting data values. Systems Analysis I, II, III Requiements detemination/equiements analysis (Analysis I) use needs? Requiements stuctuing/systems analysis (Analysis II) systems needs? Requiements fulfillment/design stategies development (Analysis III) altenative solutions Requiements analysis techniques Technique Pupose Details Infomation sought Documents/ Had data To eveal whee the oganization has been and whee it is going Quantitative documents Repots, e.g., sales Pefomance epot (Figue 4.4) Recods (Figue 4.5) Foms Qualitative documents Memos Posted signs Facts and figues Financial infomation Oganizational contexts Document types and poblems

19 Inteview JAD To collect infomation fom limited numbe of uses in an one-onone basis To collect infomation simultaneously fom key uses in a goup setting Questionnaie To gathe infomation fom many uses in a elatively shot time without the pesonal intevention of the inteviewe Diect obsevation To obtain fist hand and objective measue of uses behavio and thei physical envionment Copoate web sites Manuals Policy handbooks Undestand the backgound of the inteviewees and the oganization Establish inteview objectives Decide whom to inteview Pepae the inteviewee Stuctue the inteview (Figues ) Design questions (Figues ) Recod the inteview Pepae follow-up epot within 48 hous Select paticipants Select a site Paticipate in pesentations, discussions, consolidation of infomation gatheed Augment with GDSS Design questions Constuct scales Design the questionnaie Administe the questionnaie Analyze the data Decide what to be obseved Detemine the level of conceteness of obsevation Ceate categoies fo key activities Pepae scales, checklists, and othe mateials fo obsevation Opinions Goals Feelings Infomal pocedues New solution to a typical poblem Joint poblem-solving cultue attitudes beliefs behavio chaacteistics Activities Messages Relationships Influence

20 Decide when to obseve Jounals, newspapes, eading mateials Office lighting and colo Clothing Type of infomation used Fomality Authoity Fact Finding Techniques:- To study any system the analyst needs to do collect facts and all elevant infomation. the facts when expessed in quantitative fom ae temed as data. The success of any poject is depended upon the accuacy of available data. Accuate infomation can be collected with help of cetain methods/ techniques. These specific methods fo finding infomation of the system ae temed as fact finding techniques. Inteview, Questionnaie, Recod View and Obsevations ae the diffeent fact finding techniques used by the analyst. The analyst may use moe than one technique fo investigation. Inteview:- This method is used to collect the infomation fom goups o individuals. Analyst selects the people who ae elated with the system fo the inteview. In this method the analyst sits face to face with the people and ecods thei esponses. The inteviewe must plan in advance the type of questions he/ she is going to ask and should be eady to answe any type of question. He should also choose a suitable place and time which will be comfotable fo the espondent. The infomation collected is quite accuate and eliable as the inteviewe can clea and coss check the doubts thee itself. This method also helps gap the aeas of misundestandings and help to discuss about the futue poblems. Stuctued and unstuctued ae the two sub categoies of Inteview. Stuctued inteview is moe fomal inteview whee fixed questions ae asked and specific infomation is collected wheeas unstuctued inteview is

21 moe o less like a casual convesation whee in-depth aeas topics ae coveed and othe infomation apat fom the topic may also be obtained. Questionnaie:- It is the technique used to extact infomation fom numbe of people. This method can be adopted and used only by an skillful analyst. The Questionnaie consists of seies of questions famed togethe in logical manne. The questions ae simple, clea and to the point. This method is vey useful fo attaining infomation fom people who ae concened with the usage of the system and who ae living in diffeent counties. The questionnaie can be mailed o send to people by post. This is the cheapest souce of fact finding. What is Feasibility Study? Types of Feasibility. Explain Feasibility Study Pocess BY DINESH THAKUR Feasibility is defined as the pactical extent to which a poject can be pefomed successfully. To evaluate feasibility, a feasibility study is pefomed, which detemines whethe the solution consideed to accomplish the equiements is pactical and wokable in the softwae. Infomation such as esouce availability, cost estimation fo softwae development, benefits of the softwae to the oganization afte it is developed and cost to be incued on its maintenance ae consideed duing the feasibility study. The objective of the feasibility study is to establish the easons fo developing the softwae that is acceptable to uses, adaptable to change and confomable to established standads. Vaious othe objectives of feasibility study ae listed below. To analyze whethe the softwae will meet oganizational equiements To detemine whethe the softwae can be implemented using the cuent technology and within the specified budget and schedule To detemine whethe the softwae can be integated with othe existing softwae. Types of Feasibility

22 Vaious types of feasibility that ae commonly consideed include technical feasibility, opeational feasibility, and economic feasibility. Technical feasibility assesses the cuent esouces (such as hadwae and softwae) and technology, which ae equied to accomplish use equiements in the softwae within the allocated time and budget. Fo this, the softwae development team ascetains whethe the cuent esouces and technology can be upgaded o added in the softwae to accomplish specified use equiements. Technical feasibility also pefoms the following tasks. Analyzes the technical skills and capabilities of the softwae development team membes Detemines whethe the elevant technology is stable and established Ascetains that the technology chosen fo softwae development has a lage numbe of uses so that they can be consulted when poblems aise o impovements ae equied. Opeational feasibility assesses the extent to which the equied softwae pefoms a seies of steps to solve business poblems and use equiements. This feasibility is dependent on human esouces (softwae development team) and involves visualizing whethe the softwae will opeate afte it is developed and be opeative once it is installed. Opeational feasibility also pefoms the following tasks. Detemines whethe the poblems anticipated in use equiements ae of high pioity Detemines whethe the solution suggested by the softwae development team is acceptable Analyzes whethe uses will adapt to a new softwae

23 Detemines whethe the oganization is satisfied by the altenative solutions poposed by the softwae development team. Economic feasibility detemines whethe the equied softwae is capable of geneating financial gains fo an oganization. It involves the cost incued on the softwae development team, estimated cost of hadwae and softwae, cost of pefoming feasibility study, and so on. Fo this, it is essential to conside expenses made on puchases (such as hadwae puchase) and activities equied to cay out softwae development. In addition, it is necessay to conside the benefits that can be achieved by developing the softwae. Softwae is said to be economically feasible if it focuses on the issues listed below. Cost incued on softwae development to poduce long-tem gains fo an oganization Cost equied to conduct full softwae investigation (such as equiements elicitation and equiements analysis) Cost of hadwae, softwae, development team, and taining. Feasibility Study Pocess Feasibility study compises the following steps. 1. Infomation assessment: Identifies infomation about whethe the system helps in achieving the objectives of the oganization. It also veifies that the system can be implemented using new technology and within the budget and whethe the system can be integated with the existing system. 2. Infomation collection: Specifies the souces fom whee infomation about softwae can be obtained. Geneally, these souces include uses (who will opeate the softwae), oganization (whee the softwae will be used), and the softwae development team (which undestands use equiements and knows how to fulfill them in softwae). 3. Repot witing: Uses a feasibility epot, which is the conclusion of the feasibility study by the softwae development team. It includes the ecommendations whethe the softwae development should continue. This epot may also include infomation about changes in the softwae scope, budget, and schedule and suggestions of any equiements in the system. 4. Geneal infomation: Descibes the pupose and scope of feasibility study. It also descibes system oveview, poject efeences,

24 aconyms and abbeviations, and points of contact to be used. System oveview povides desciption about the name of the oganization esponsible fo the softwae development, system name o title, system categoy, opeational status, and so on. Poject efeences povide a list of the efeences used to pepae this document such as documents elating to the poject o peviously developed documents that ae elated to the poject. Aconyms and abbeviations povide a list of the tems that ae used in this document along with thei meanings. Points of contact povide a list of points of oganizational contact with uses fo infomation and coodination. Fo example, uses equie assistance to solve poblems (such as toubleshooting) and collect infomation such as contact numbe, addess, and so on. Cost benefit analysis (CBA):- sometimes called benefit cost analysis (BCA), is a systematic appoach to estimating the stengths and weaknesses of altenatives (fo example in tansactions, activities, functional business equiements); it is used to detemine options that povide the best appoach to achieve benefits while peseving savings. The CBA is also defined as a systematic pocess fo calculating and compaing benefits and costs of a decision, policy (with paticula egad to govenment policy) o (in geneal) poject. Boadly, CBA has two main puposes: 1. To detemine if an investment/decision is sound (justification/feasibility) veifying whethe its benefits outweigh the costs, and by how much; 2. To povide a basis fo compaing pojects which involves compaing the total expected cost of each option against its total expected benefits. CBA is elated to, but distinct fom cost-effectiveness analysis. In CBA, benefits and costs ae expessed in monetay tems, and ae adjusted fo the time value of money, so that all flows of benefits and flows of poject costs ove time (which tend to occu at diffeent points in time) ae expessed on a common basis in tems of thei net pesent value. Closely elated, but slightly diffeent, fomal techniques include cost-effectiveness analysis, cost utility analysis, isk benefit analysis, economic impact analysis, fiscal impact analysis,

25 and social etun on investment (SROI) analys Cost-Benefit Analysis:- When new systems ae poposed, the cost is a majo consideation which impacts on the decision to accept o eject the poposed system. The people funding the system want to know whethe they will get a good etun fo the money they invest in the system. In lage companies thee is often competition to get access to financial esouces fo innovative pojects. So, to win suppot fo a poject, estimates of costs and benefits must be calculated. This is called a cost-benefit analysis. Thee ae two main aeas fo costs: the development costs and the opeating costs once a system is intoduced. An example of how these costs can be estimated is shown below. Estimated costs fo client-seve system altenative DEVELOPMENT COSTS No. Pesonnel Estimated costs 3 System analysts (400 hous $80 pe h) $96,000 3 Pogamme/analysts (250 hous $60 pe $45,000 h) 1 Web designe (100 hous $35 pe h) $ Telecommunications specialist (50 hous $2250 $45 pe h) 1 System achitect (100 hous $60 pe h) $ Database specialist (50 hous $40 pe h) $2000 No. Expenses Estimated costs 7 Deamweave $900 pe student $6300 No. New hadwae and softwae Estimated costs 1 Development seve $18,700 1 Seve softwae $1500

26 15 Deamweave licences ($150 ea) $ Pentium desktop machines ($1700 ea) $68,000 Total development costs $251,500 PROJECTED ANNUAL OPERATING COSTS Pesonnel Estimated costs Pogamme/analysts (125 hous $25.00 pe h) $3125 No. Expenses Estimated costs 1 Maintenance ageement fo Pentium $995 1 Maintenance ageement fo seve DBMS $525 softwae $80 pe month $960 Total pojected opeating costs $5605 Thee ae tangible and intangible costs and tangible and intangible benefits. Tangibles can be easily calculated; intangibles cannot. Tangible costs Tangible costs include the following. 1 Pesonnel Costs salaies of analysts, pogammes, consultants, data enty pesonnel, etc costs fo taines and employees' time 2 Costs fo equipment fo the new system compute hadwae space/ooms funitue

27 3 Suppoting mateial stationey photocopying 4 Conveting to new system 5 Miscellaneous designing new pocesses and pocedues unning new and old systems togethe fo a peiod of time tavel oveheads telephone Intangible costs Intangible costs include loss of custome good will staff distess supplie confusion when pocesses change Intangible benefits Although the costs of intangible benefits cannot be easily calculated, it is vey impotant to identify them. Often intangible benefits may make the diffeence between a poject being funded o not being funded. Some intangible benefits ae impoved wok pactices and employee moale custome access to account details ove the telephone up to date poduct infomation on the web inceased loyalty of customes by offeing competitions and pizes To detemine whethe a poposed system is cost-effective thee techniques ae often used. These involve fomulas to calculate the time value of money. This is based on the assumption that a dolla today is woth moe than a dolla next yea, because if you invest a dolla today you would have moe that a dolla next yea. The thee techniques ae

28 payback analysis etun-on-investment analysis net pesent values. UNIT 3 d DATA MODELLING Taditionally, data models have been built duing the analysis and design phases of a poject to ensue that the equiements fo a new application ae fully undestood. A data model can be thought of as a flowchat that illustates the elationships between data. Although captuing all the possible elationships in a data model can be vey time-intensive, it's an impotant step that shouldn't be ushed. Well-documented conceptual, logical and physical data models allow stake-holdes to identify eos and make changes befoe any pogamming code has been witten. Data modeles often use multiple models to view the same data and ensue that all pocesses, entities, elationships and data flows have been identified. Thee ae seveal diffeent appoaches to data modeling, including: Conceptual Data Modeling - identifies the highest-level elationships between diffeent entities. Entepise Data Modeling - simila to conceptual data modeling, but addesses the unique equiements of a specific business. Logical Data Modeling - illustates the specific entities, attibutes and elationships involved in a business function. Seves as the basis fo the ceation of the physical data model.

29 Physical Data Modeling - epesents an application and database-specific implementation of a logical data model. Dawing Data Flow Diagam (DFD) Repesent the flow of data though an infomation Data flow diagam (DFD) pojects an oveview of an infomation system though epesenting the poduction and eceive of 'data'. Visual Paadigm featues all the DFD tools you need to daw pofessional DFD and geneate complete DFD specification. You can also link up you DFD and business pocess diagam (BPD) fo connecting you system pocesses and business activities. Data Flow Diagam:- Examples - Food Odeing System Data Flow Diagam (DFD) povides a visual epesentation of the flow of infomation (i.e. data) within a system. By dawing a Data Flow Diagam, you can tell the infomation povided by and deliveed to someone who takes pat in system pocesses, the infomation needed in ode to complete the pocesses and the infomation needed to be stoed and

30 accessed. This aticle descibes and explain Data Flow Diagam (DFD) by using a food odeing system as an example. The Food Odeing System Example Context DFD A context diagam is a data flow diagam that only shows the top level, othewise known as Level 0. At this level, thee is only one visible pocess node that epesents the functions of a complete system in egads to how it inteacts with extenal entities. Some of the benefits of a Context Diagam ae: Shows the oveview of the boundaies of a system No technical knowledge is equied to undestand with the simple notation Simple to daw, amend and elaboate as its limited notation The figue below shows a context Data Flow Diagam that is dawn fo a Food Odeing System. It contains a pocess (shape) that epesents the system to model, in this case, the "Food Odeing System". It also shows the paticipants who will inteact with the system, called the extenal entities. In this example, Supplie, Kitchen, Manage and Custome ae the entities who will inteact with the system. In between the pocess and the extenal entities, thee ae data flow (connectos) that indicate the existence of infomation exchange between the entities and the system.

31 Context DFD is the entance of a data flow model. It contains one and only one pocess and does not show any data stoe. Level 1 DFD The figue below shows the level 1 DFD, which is the decomposition (i.e. beak down) of the Food Odeing System pocess shown in the context DFD. Read though the diagam and then we will intoduce some of the key concepts based on this diagam. The Food Ode System Data Flow Diagam example contains thee pocesses, fou extenal entities and two data stoes. Based on the diagam, we know that a Custome can place an Ode. The Ode Food pocess eceives the Ode, fowads it to the Kitchen, stoe it in the Ode data stoe, and stoe the updated Inventoy details in the Inventoy data stoe. The pocess also delive a Bill to the Custome.

32 Manage can eceive Repots though the Geneate Repots pocess, which takes Inventoy details and Odes as input fom the Inventoy and Ode data stoe espectively. Manage can also initiate the Ode Inventoy pocess by poviding Inventoy ode. The pocess fowads the Inventoy ode to the Supplie and stoes the updated Inventoy details in the Inventoy data stoe. Data Flow Diagam Tips and Cautions Tips Pocess labels should be veb phases; data stoes ae epesented by nouns A data stoe must be associated to at least a pocess An extenal entity must be associated to at least a pocess Don't let it get too complex; nomally 5-7 aveage people can manage pocesses DFD is non-deteministic - The numbeing does not necessaily indicate sequence, it's useful in identifying the pocesses when discussing with uses Data stoes should not be connected to an extenal entity, othewise, it would mean that you'e giving an extenal entity diect access to you data files Data flows should not exist between 2 extenal entities without going though a pocess A pocess that has inputs but no outputs is consideed to be a black-hole pocess Data dictionay. A data dictionay:- o metadata epositoy, as defined in the IBM Dictionay of Computing, is a "centalized epositoy of infomation about data such as meaning, elationships to othe data, oigin, usage, and fomat. The tem can have one of seveal closely elated meanings petaining to databases and database management systems (DBMS):

33 A document descibing a database o collection of databases An integal component of a DBMS that is equied to detemine its stuctue A piece of middlewae that extends o supplants the native data dictionay of a DBMS A decision tee:- is a flowchat-like stuctue in which each intenal node epesents a "test" on an attibute (e.g. whethe a coin flip comes up heads o tails), each banch epesents the outcome of the test and each leaf node epesents a class label (decision taken afte computing all attibutes). The paths fom oot to leaf epesents classification ules. In decision analysis a decision tee and the closely elated influence diagam ae used as a visual and analytical decision suppot tool, whee the expected values (o expected utility) of competing altenatives ae calculated. A decision tee consists of 3 types of nodes: 1. Decision nodes - commonly epesented by squaes 2. Chance nodes - epesented by cicles 3. End nodes - epesented by tiangles Decision tees ae commonly used in opeations eseach and opeations management. If in pactice decisions have to be taken online with no ecall unde incomplete knowledge, a decision tee should be paalleled by a pobability model as a best choice model o online selection model algoithm. Anothe use of decision tees is as a desciptive means fo calculating conditional pobabilities. Decision tees, influence diagams, utility functions, and othe decision analysis tools and methods ae taught to undegaduate students in

34 schools of business, health economics, and public health, and ae examples of opeations eseach o management science methods. Decision tee building blocks:- Decision tee elements Decision table Decision tables ae a pecise yet compact way to model complex ule sets and thei coesponding actions. Decision tables, like flowchats, if-then-else, and switchcase statements, associate conditions with actions to pefom, but in many cases do so in a moe elegant way. In the 1960s and 1970s a ange of "decision table based" languages such as File tab wee popula fo business pogamming. The fou quadants Conditions Condition altenatives Actions Action enties Each decision coesponds to a vaiable, elation o pedicate whose possible values ae listed among the condition altenatives. Each action is a pocedue o opeation to pefom, and the enties specify whethe (o in what ode) the action is to be pefomed fo the set of condition altenatives the enty coesponds to. Many decision tables include in thei condition altenatives the don't cae symbol, a hyphen. Using don't caes can simplify decision tables, especially when a given condition has little influence on the actions to be pefomed. In some cases, entie conditions thought to be impotant initially ae found to be ielevant when none of the conditions influence which actions ae pefomed.

35 Entity Relationship Diagam An entity elationship diagam (ERD) shows the elationships of entity sets stoed in a database. An entity in this context is a component of data. In othe wods, ER diagams illustate the logical stuctue of databases. At fist glance an entity elationship diagam looks vey much like a flowchat. It is the specialized symbols, and the meanings of those symbols, that make it unique. System deign:-systems design is the pocess of defining the achitectue, components, modules, intefaces, and data fo a system to satisfy specified equiements. Systems design could be seen as the application of systems theoy to poduct development. Thee is some ovelap with the disciplines of systems analysis, systems achitectue and systems engineeing. o o o 1.1Achitectual design 1.2Logical design 1.3Physical design

36 Until the 1990s, systems design had a cucial and espected ole in the data pocessing industy. In the 1990s,standadization of hadwae and softwae esulted in the ability to build modula systems. The inceasing impotance of softwae unning on geneic platfoms has enhanced the discipline of softwae engineeing. Object-oiented analysis and design methods ae becoming the most widely used methods fo compute systems design. The UML has become the standad language in object-oiented analysis and design. [ It is widely used fo modeling softwae systems and is inceasingly used fo high designing non-softwae systems and oganizations. [ Achitectual desig] The achitectual design of a system emphasizes the design of the systems achitectue that descibes the stuctue,behavio and moe views of that system and analysis. Logical design The logical design of a system petains to an abstact epesentation of the data flows, inputs and outputs of the system. This is often conducted via modelling, using an ove-abstact (and sometimes gaphical) model of the actual system. In the context of systems, designs ae included. Logical design includes entity-elationship diagams (ER diagams). Physical design[ The physical design elates to the actual input and output pocesses of the system. This is explained in tems of how data is input into a system, how it is veified/authenticated, how it is pocessed, and how it is displayed. In physical design, the following equiements about the system ae decided. 1. Input equiement, 2. Output equiements, 3. Stoage equiements, 4. Pocessing equiements, 5. System contol and backup o ecovey. Put anothe way, the physical potion of systems design can geneally be boken down into thee sub-tasks: 1. Use Inteface Design 2. Data Design 3. Pocess Design

37 Use Inteface Design is concened with how uses add infomation to the system and with how the system pesents infomation back to them. Data Design is concened with how the data is epesented and stoed within the system. Finally, Pocess Design is concened with how data moves though the system, and with how and whee it is validated, secued and/o tansfomed as it flows into, though and out of the system. At the end of the systems design phase, documentation descibing the thee sub-tasks is poduced and made available fo use in the next phase. Physical design, in this context, does not efe to the tangible physical design of an infomation system. To use an analogy, a pesonal compute's physical design involves input via a keyboad, pocessing within the CPU, and output via a monito, pinte, etc. It would not concen the actual layout of the tangible hadwae, which fo a PC would be a monito, CPU, motheboad, had dive, modems, video/gaphics cads, USB slots, etc. It involves a detailed design of a use and a poduct database stuctue pocesso and a contol pocesso. The H/S pesonal specification is developed fo the poposed system. Nomalization of Database Database Nomalisation is a technique of oganizing the data in the database. Nomalization is a systematic appoach of decomposing tables to eliminate data edundancy and undesiable chaacteistics like Insetion, Update and Deletion Anamolies. It is a multi-step pocess that puts data into tabula fom by emoving duplicated data fom the elation tables. Nomalization is used fo mainly two pupose, Eliminating eduntant (useless) data. Ensuing data dependencies make sense i.e data is logically stoed. Nomalization of Database Database Nomalisation is a technique of oganizing the data in the database. Nomalization is a systematic appoach of decomposing tables to eliminate data edundancy and undesiable chaacteistics like Insetion, Update and Deletion Anamolies. It is a multi-step pocess that puts data into tabula fom by emoving duplicated data fom the elation tables.

38 Nomalization is used fo mainly two pupose, Eliminating eduntant(useless) data. Ensuing data dependencies make sense i.e data is logically stoed. Poblem Without Nomalization Without Nomalization, it becomes difficult to handle and update the database, without facing data loss. Insetion, Updation and Deletion Anamolies ae vey fequent if Database is not Nomalized. To undestand these anomalies let us take an example of Student table. S_id S_Name S_Addess Subject_opted 401 Adam Noida Bio 402 Alex Panipat Maths 403 Stuat Jammu Maths 404 Adam Noida Physics Updation Anamoly : To update addess of a student who occus twice o moe than twice in a table, we will have to update S_Addess column in all the ows, else data will become inconsistent. Insetion Anamoly : Suppose fo a new admission, we have a Student id(s_id), name and addess of a student but if student has not opted fo any subjects yet then we have to inset NULL thee, leading to Insetion Anamoly.

39 Deletion Anamoly : If (S_id) 401 has only one subject and tempoaily he dops it, when we delete that ow, entie student ecod will be deleted along with it. Nomalization Rule Nomalization ule ae divided into following nomal fom. 1. Fist Nomal Fom 2. Second Nomal Fom 3. Thid Nomal Fom 4. BCNF Fist Nomal Fom (1NF) As pe Fist Nomal Fom, no two Rows of data must contain epeating goup of infomation i.e each set of column must have a unique value, such that multiple columns cannot be used to fetch the same ow. Each table should be oganized into ows, and each ow should have a pimay key that distinguishes it as unique. The Pimay key is usually a single column, but sometimes moe than one column can be combined to ceate a single pimay key. Fo example conside a table which is not in Fist nomal fom Student Table : Student Age Subject Adam 15 Biology, Maths Alex 14 Maths Stuat 17 Maths

40 In Fist Nomal Fom, any ow must not have a column in which moe than one value is saved, like sepaated with commas. Rathe than that, we must sepaate such data into multiple ows. Student Table following 1NF will be : Student Age Subject Adam 15 Biology Adam 15 Maths Alex 14 Maths Stuat 17 Maths Using the Fist Nomal Fom, data edundancy inceases, as thee will be many columns with same data in multiple ows but each ow as a whole will be unique. Second Nomal Fom (2NF) As pe the Second Nomal Fom thee must not be any patial dependency of any column on pimay key. It means that fo a table that has concatenated pimay key, each column in the table that is not pat of the pimay key must depend upon the entie concatenated key fo its existence. If any column depends only on one pat of the concatenated key, then the table fails Second nomal fom. In example of Fist Nomal Fom thee ae two ows fo Adam, to include multiple subjects that he has opted fo. While this is seachable, and follows Fist nomal fom, it is an inefficient use of space. Also in the above Table in Fist Nomal Fom, while the candidate key is {Student, Subject}, Age of Student only depends on Student column, which is incoect as pe Second Nomal Fom. To achieve second nomal fom, it would be helpful to split out the subjects into an independent table, and match them up using the student names as foeign keys.

41 New Student Table following 2NF will be : Student Age Adam 15 Alex 14 Stuat 17 In Student Table the candidate key will be Student column, because all othe column i.e Age is dependent on it. New Subject Table intoduced fo 2NF will be : Student Subject Adam Biology Adam Maths Alex Maths Stuat Maths In Subject Table the candidate key will be {Student, Subject} column. Now, both the above tables qualifies fo Second Nomal Fom and will neve suffe fom Update Anomalies. Although thee ae a few complex cases in which table in Second Nomal Fom suffes Update Anomalies, and to handle those scenaios Thid Nomal Fom is thee. Thid Nomal Fom (3NF) Thid Nomal fom applies that evey non-pime attibute of table must be dependent on pimay key, o we can say that, thee should not be

42 the case that a non-pime attibute is detemined by anothe non-pime attibute. So this tansitive functional dependency should be emoved fom the table and also the table must be in Second Nomal fom. Fo example, conside a table with following fields. Student_Detail Table : Student_id Student_name DOB Steet city State Zip In this table Student_id is Pimay key, but steet, city and state depends upon Zip. The dependency between zip and othe fields is called tansitive dependency. Hence to apply 3NF, we need to move the steet, city and state to new table, with Zip as pimay key. New Student_Detail Table : Student_id Student_name DOB Zip Addess Table : Zip Steet city state The advantage of emoving tanstive dependency is, Amount of data duplication is educed. Data integity achieved. Boyce and Codd Nomal Fom (BCNF) Boyce and Codd Nomal Fom is a highe vesion of the Thid Nomal fom. This fom deals with cetain type of anamoly that is not handled by 3NF. A 3NF table which does not have multiple ovelapping candidate keys is said to be in BCNF. Fo a table to be in BCNF, following conditions must be satisfied: R must be in 3d Nomal Fom

43 and, fo each functional dependency ( X -> Y ), X should be a supe Key. FORMS:- People ead fom foms, wite on foms and spend hous handling foms and filing foms. The data the foms cay come fom people and the infomational output goes to people. Fom is a tool with a message. It is the physical caie of data-of infomation. It is an eithe an authoity fo action o a equest fo action. Classification of foms: A pinted fom is geneally classified by what it does in the system. Thee ae thee pimay classifications 1.Action: This type of fom equests the use to do something. Example: puchase odes. 2.Memoy: This fom is a ecod of histoical data that emains in a file, is used fo efeence, and seves as contol on key details. Example: Inventoy ecods, puchase ecods

44 3.Repot: This fom guides supevisos and othe administatos in the activities. It povides data on a poject o a job. Example: pofit and loss statements, sales analysis epot Requiements of fom design: Fom design follows analyzing foms. Since the pupose of a fom is to communicate effectively though foms design, thee ae seveal majo equiements. 1.Identification and woding: The fom title must clealy identify its pupose. Columns and ows should be labeled to avoid confusion. The fom should also be identified by fim name o code numbe to make it easy to eode. 2.Maximum eadability and use: The fom must be easy to use and fill out. It should be legible, intelligible and uncomplicated. Ample witing space must be povided fo inseting data. 3.Physical factos: The foms composition, colo, layout and pape stock should lend themselves to easy eading. Pages should be numbeed when multipage epots ae being geneated fo the use. 4.Ode of data items: The data equested should eflect a logical sequence. Related data should be in adjacent positions. Data copied fom souce documents should be in the same sequence on both foms. 5.Ease of data enty: If used fo data enty, the fom should have field positions indicated unde each column of data and should have some indication of whee decimal points ae. 6.Size and aangement: The fom must be easily stoed and filed. It should povide fo signatues. Impotant items must be in a pominent action on the fom. 7.Use of instuctions: The instuctions that accompany a fom should clealy show how it is used and handled. 8.Efficiency consideations: The fom must be cost effective. This means eliminating unnecessay data and facilitating eading lines acoss the fom.

45 9.Type of epot: Foms design should also conside whethe the content is executive summay, intemediate manageial infomation, o suppoting data. The use equiements fo each type detemine the final fom design. Cabon pape as fom copie: Cabon pape is one way of duplicating infomation in a fom. Thee ae two types of cabon, classified by the action they encounte 1.Glide action cabon is inseted between a set of foms. It allows the glide action of the pencil to tansfe dye to the suface of the sheet beneath. 2.Hamme action cabon is used in typewites and line pintes of computes. The hamme action of the keys tansfes the cabon coating to the sheet beneath. Vaious methods of tansfeing impessions between copies ae as follows 1.One time cabon: It is made of inexpensive Kaftex pape. It is inteleaved between two sheets in the fom. It is used once and then thown away. It is the most cost-effective fo multipat foms. 2.Cabon backed pape: The back of each fom copy is coated with cabon, which tansfes data to the copy beneath. 3.NCR ( No Cabon Requied) pape: The top sheet is chemically teated with invisible dye, that allows impessions to be tansfeed to the next lowe copy. It is the cleanest and the costliest method. Easing emoves the coating pemanently. GRAPHICAL INTERFACE:- In compute science, a gaphical use inteface (GUI ), is a type of use inteface that allows uses to inteact with electonic devices though gaphical icons and visual indicatos such as seconday notation, instead of text-based use intefaces, typed command labels o text navigation. GUIs wee intoduced in eaction to the peceived steep leaning cuve of command-line intefaces which equie commands to be typed on a compute keyboad. The actions in a GUI ae usually pefomed though diect manipulation of the gaphical elements Beyond computes, GUIs ae used in many handheld mobile devices such as MP3 playes, potable media playes, gaming devices,smatphones and smalle household, office and industial contols. The tem GUI tends not to be applied to

46 othe lowe-display esolution types of intefaces, such as video games (whee head-up display (HUD) is pefeed), o not esticted to flat sceens, like volumetic displays because the tem is esticted to the scope of two-dimensional display sceens able to descibe geneic infomation, in the tadition of the compute science eseach at the Xeox Palo Alto Reseach Cente (PARC). Machine-eadable medium In telecommunications and computing a machine-eadable medium (automated data medium) is a medium capable of stoing data in a fomat eadable by a mechanical device (athe than human eadable). Examples of machine-eadable media include magnetic media such as magnetic disks, cads, tapes, and dums,punched cads and pape tapes, optical disks, bacodes and magnetic ink chaactes. ISBN epesented as EAN-13 ba code showing both machine-eadable bas and human-eadable digits Common machine-eadable technologies include magnetic ecoding, pocessing wavefoms, and bacodes. Optical chaacte ecognition (OCR) can be used to enable machines to ead infomation available to humans. Any infomation etievable by any fom of enegy can be machine-eadable. Output Design:- One of the most impotant featues of an infomation system fo uses is the output it poduces. Without quality output, the entie system may appea to be so unnecessay that uses will avoid using it, possibly causing it to fail. The tem output applies to any infomation poduced by an 9infomation system, whethe pinted o displayed. When analyst design compute output they - Identify specific output that is needed to meet the infomation equiements. - Select methods fo pesenting infomation. - Ceate document, epot o othe fomats that contain infoma on poduced by the system. Objec ves of output The output fom an infomation system should accomplish one o moe of the following objectives :- Convey infomation about past activities, cuent status, o pojection of the futue. - Signal impotant events, oppotunities, poblems o wanings. - Tigge an action. - Confim an Types of output Whethe the output is a fomatted epot o a simple listing of the contents of a file, a compute pocess will poduce the output. System output may be : - A Repot - A Document - A Message Depending upon the cicumstances and the contents, the output may be displayed o pinted.

47 Output contents oiginate fom the following souces : - Retieval fom a data stoe. - Tansmission fom [pocess o system activity. Diectly fom an input souce. OUTPUT CONTROLS: OPPORTUNITIES AND CHALLENGES The good news is that pefoming a eview of output contols is not an expensive o labo intensive execise. One should be able to tackle a few citical output contols each yea until you have coveed the key contols. The eviews can be conducted in weeks, not months and the intelligence gleamed fom these execises will help to impove you oveall contol envionment. To stat, define the scope of the output contols eview. One simple way to decide is to stat with the most citical custome output contols. (Custome confimations, monthly financial statements, pospectus delivey, web site contols, etc.) Moe complex output contols may include system application intefaces with speadsheets and othe upsteam applications o change contols fo financial databases. These moe complex output contols should be segegated into citical categoies such as financial output contols, opeations output contols, administative output contols, o maintenance output contols whee one system elies on the accuacy of anothe system to pocess data o complete tansactional pocessing. Segegating these contols allows you to pioitize and easily manage the cycle of you eview of these contols. If you conduct annual SysTust o SAS 70 audits, some of these contols will be tested as pat of the independent exams pefomed by extenal auditos. Extenal auditos inceasingly ely on systems contols fo assuance that financial contols ae opeating effectively. Howeve, one should not ely solely on these examinations to assue themselves that all of thei citical output contols ae coveed. Once you have identified the scope of you eview, assemble a small team of subject matte expets to begin the assessment pocess. Stat with a simple assessment map of the contols: input, activity, output. You SMEs should be able to detemine who is accountable fo the contol, how the contol is suppose to wok, how to validate o test its accuacy, and to povide policies and pocedues that ensue the contols ae opeating as designed.

48 Developing a visual map is citical to ensue all ae in ageement that the key contols ae pesented in entiety and no gaps exist. Visual maps also help illuminate inte-dependencies acoss depatments o othe, moe fomal business line accountabilities. (Think of how many times one depatment believed anothe ensued the accuacy of data, only to find othewise when a seious failue occued.) Documenting in naative fom the contols and handoffs seves to claify the contols opeation and stengthen gaps that may exist. The level of detail that one chooses to use is citical hee. I would suggest that the eviews and details emain high level enough to ensue that an accuate epesentation of the contols map show the key contols and accountabilities. The goal of the execise is to gain assuance that the output contols ae accuate and opeating effectively. How do you know questions typically lead to the desied esponse. The level of detail is subjective to the SMEs pefoming the assessment and the level of assuance one obtains fom the documentation, epots, o tests pefomed on the contols. What ae Output Devices? An output device is any piece of hadwae used to communicate the esult of pocessing caied by the CPU. Audio o visual devices ae the two main foms used with pesonal computes but in contol systems, actuatos can also be used to contol motos and so on. Compute output can be boadly split into thee diffeent types: Had Copy - this is whee something phyiscal that can be touched, such a s piece of pape is poduced. Soft Copy - this is whee no physical output is ceated, the output is puely visual in the fom of light Data - The compute geneates an electical signal that can opeate some othe device completely sepaate (a peipheal) to the compute system. Each of these type of device ae descibed moe fully in this section of the website Diffeent Types of Compute Output

49 UNIT 4 TH :- Modula design, o "modulaity in design", is a design appoach that subdivides a system into smalle pats called modules o skids, that can be independently ceated and then used in diffeent systems. A modula system can be chaacteized by functional patitioning into discete scalable, eusable modules, igoous use of well-defined modula intefaces, and making use of industy standads fo intefaces. Besides eduction in cost (due to less customization, and shote leaning time), and flexibility in design, modulaity offes othe benefits such as augmentation (adding new solution by meely plugging in a new module), and exclusion. Examples of modula systems ae cas, computes, pocess systems, sola panels and wind tubines, elevatos and modula buildings. Ealie examples include looms, aiload signalling systems, telephone exchanges, pipe ogans and electic powe distibution systems. Computes use modulaity to ovecome changing custome demands and to make the manufactuing pocess moe adaptive to change (see modula pogamming) ] Modula design is an attempt to combine the advantages of standadization (high volume nomally equals low manufactuing costs) with those of customization. A downside to modulaity (and this depends on the extent of modulaity) is that low quality modula systems ae not optimized fo pefomance. This is usually due to the cost of putting up intefaces between modules.