Software Design and Development notes (Summary) HSC Information, Software & Technology. Year 2017 Mark Pages 14 Published Jan 2, 2018

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HSC Information, Software & Technology Year 2017 Mark 93.

1 HSC Information, Software & Technology Year 2017 Mark Pages 14 Published Jan 2, 2018 Software Design and Development notes (Summary) By Tom (98.2 ATAR)

Powered by TCPDF (www.tcpdf.org) Your notes author, Tom. Tom achieved an ATAR of 98.

2 Powered by TCPDF ( Your notes author, Tom. Tom achieved an ATAR of 98.2 in 2017 while attending Sydney Church of England Grammar School Currently studying Biomedical engineering at The University of New South Wales Achievements: E4 in Mathematics Extension 1 E4 in Mathematics Extension 2 Band 6 in Physics Band 5 in Chemistry Band 6 in Software Design and Development Band 5 in Standard English Tom says: I graduated in 2017 from Sydney Church of England Grammar School. I have a strong focus on STEM subjects, with strong results in Maths Extension 1 and 2,Physics and Software Design and Development. I also topped my class for both Standard English and Software Design and Development.

3 Software notes Social and ethical issues Rights and responsibilities of software developers Issue Rights Responsibilities Authorship Protection of their products against theft and modification without permission Acknowledge the authors and sources used in development Reliability Right to avoid OS, hardware/ program problems which may interfere with the program Check that the product works with the OS, ensure that there are no runtime errors. And that it runs as it should Quality Codes that follow high standards. Thorough testing, meets users needs. Response to problems Code of conduct Viruses Not to be harassed by basic user created problems That others follow the same ethical standards Protection of their products with users, by users using updated antivirus solutions Provide troubleshooting methods, online help, user manuals, free bug fixes ASAP Follow the standards set by the organisation to which they belong Do not distribute viruses Software piracy and copyright There are four main classifications for licensing Commercial o Most software purchased from software publishers/ computer stores etc. Shareware o You require a license to use, however you are allowed to make and distribute copies. o A free trial is provided, however after the trial ends you must pay for it to continue using it Freeware o Can be distributed freely as long as one does not receive a profit from doing so o Cannot alter freeware Public domain o When the developer explicitly relinquishes all rights to the software o Everyone is allowed to use how they wish (copy / modify/ distribute) Ownership vs Licensing o When someone purchases a license to use a program, they do not own it o They are buying use of the program, not the program itself o Ownership can be purchased when a program is developed specifically for a business Application of software development approaches Software development approaches Agile vs Structured These are the two main approaches you need to know, the other approaches (prototyping, RAD and end user, are important, but these are more likely to come up in exams)

4 Approach Advantages Disadvantages Agile Flexible design model which allows for adaptive planning and evolutionary development Hard to predict in terms of timelines and budgets Quite vague in the development process as there is comparatively Only work on small modules at a time allowing for adjustment if requirements change little planning and scheduling Active user/ client involvement is required throughout the whole process which can be a problem, Beneficial when the end solution is open to change because the coding takes longer than in the Structured approach due This method facilitates interaction and communication throughout the whole project Structured The emphasis of the structured approach is the project plan This requires heavy documentation and very extensive planning You are able to estimate timetables and budgets more clearly due to this increased planning The coding process is faster as the whole process and solutions have been planned out extensively More secure and safe, eg. can handle developers quitting as the documentation allows for a new developer to understand the program easily to the limited planning Having a person drop out of the project could be catastrophic to the program as it is very hard for a new developer to come in and understand the code that others have writing and understand how the program works. Incredibly rigid and inflexible, altering the project design in any way throughout the development of the program can result is massive delays and can be very difficult to do Once a stage has been completed it is very hard if not impossible to make changes to it Full requirements need to be gathered upfront. Feedback and testing are deferred to very late in the program, meaning feedback is very difficult to respond to, as major changes based on this feedback cannot really be implemented Very expensive process Employment trends in software development Outsourcing o It is becoming more common for businesses to contract other developers to write the code for their programs. This can be because they are more skilled and experienced in developing these programs or because the business itself does not have the expertise of resources to make the program itself. o Benefits of outsourcing include: Reduced costs High quality from specialists Resources not available internally

5 Powered by TCPDF ( o Faster development times Specialists respond better to change Difficulties with outsourcing Communication If a business is outsourcing to a company in another country, different languages might result in communication difficulty Communicating online can be difficult, especially if it is over text chat, or . Voice communication over programs like skype reduce this problem, but communicating in person will always be best. Time zones can mean it can be hard to find a good time to communicate about the changing needs to the program. This results in less communication which means that the client s needs are unlikely to be fully met Implementation of software solution Language syntax required for software solutions Extended Backus-Naur Form (EBNF) Symbol Meaning = Is defined as Indicates a choice between symbols < > Used to specify a term that will be subsequently defined [ ] Used to indicate an optional part of a definition { } Indicate a possible repetition (0 or more times) ( ) Used to group elements together For example, if we made o Letter = A B C D o Digit = o Identifier = <letter> {<letter><digit>} An identifier could be a letter followed by any number of letter then digit pairs. o Eg. AB4D2F3 o Eg. B o Eg. AA3A3D5 But any set of numbers and letters that doesn t follow this required pattern would no be defined as an identifier o Eg. 6 o Eg. 6A4B3 o Eg. EE4AA4 A terminal symbol is an item for which there is no need for further definition. It may be a symbol or a reserved word (such as PRINT, IF ) Railroad Diagrams This is an alternative, graphical method used to define the syntax of a programming language. Rectangles are used to enclose non-terminal symbols, that is, symbols that will be further defined. Circles or rounded rectangles are used to enclose terminal symbols. There is no need for further definition of such items. They may be a symbol or a reserved word.

Which one of the following terms describes the physical components of a computer system?

Exercise 23 1.1.1 Which one of the following terms describes the physical components of a computer system? a. Hardware. b. Freeware. c. Software. d. Courseware. 1.1.2 Which one of the following is a portable