Personal Automated Chef (PAC)

Transcription

1 Personal Automated Chef (PAC) 06 April 2012 Trade Study Prepared for EN Systems Engineering Master s Project Prepared by Brian A. Karlow, Systems Engineer 2012_07_21_Karlow_Trade_Sudy_B 1/19

2 Table of Contents Summary... 4 Introduction... 4 Trade Study Method... 4 Requirements and Functions... 5 Alternative Pre Selectors Selection Criteria Pre Selectors... 8 Selection Criteria... 9 Pair Wise Comparison Utility Curves Trade Study Matrix Sensitivity Analysis Conclusions and Recommendations References _07_21_Karlow_Trade_Sudy_B 2/19

3 List of Figures and Tables Table 1: PAC Data Storage Size Estimates... 7 Table 2: Tablet Computer Trade Study Pair Wise Comparison (not including cost) Table 3: Tablet Computer Trade Study Pair Wise Comparison (including cost) Table 4: Pair Wise Comparison Scale Figure 1: Screen Size Utility Curve Figure 2: Resolution Utility Curve Figure 3: Processor Speed Utility Curve Figure 4: Operating Temperature Utility Curve Figure 5: Cost Utility Curve Table 5: Tablet Computer Trade Study Comparison Matrix (not including cost) Table 6: Tablet Computer Trade Study Comparison Matrix (including cost) Table 7: Comparison Matrix (not including cost) Screen Size Sensitivity Table 8: Comparison Matrix (not including cost) Resolution Sensitivity Table 9: Comparison Matrix (not including cost) Speed Sensitivity Table 10: Comparison Matrix (not including cost) Temperature Sensitivity Table 11: Comparison Matrix (including cost) Screen Size Sensitivity Table 12: Comparison Matrix (including cost) Resolution Sensitivity Table 13: Comparison Matrix (including cost) Speed Sensitivity Table 14: Comparison Matrix (including cost) Temperature Sensitivity Table 15: Comparison Matrix (including cost) Cost Sensitivity _07_21_Karlow_Trade_Sudy_B 3/19

4 Summary The Apple ipad 3 tablet computer was selected to meet the requirements of the Personal Automated Chef (PAC) system. The ipad will perform the functions allocated to both the Human-Machine Interface (HMI) touch-screen display and computer hardware elements. The selection of the ipad is the result of a Pair-Wise Comparison involving the criteria of screen size, screen resolution, processor speed, and operating temperature limit. For additional information, cost was also evaluated in the trade study. The ipad outperformed four other alternatives in the trade study: the HP Touchpad, Tab 7.0, Sony SGPT112US, and AT105-T1032. Introduction A trade study was performed in order to objectively select a specific touch-screen (tablet) computer component to be used in the Personal Automated Chef (PAC) system. Initially, the trade study was to focus only on a touch-screen display (without a computer). Preliminary market research, however, demonstrated that there is a highly-competitive market for consumer electronics with a wide availability of tablet computers technologically capable of meeting the requirements and performing the functions of the PAC system. The market for a computer-less touchscreen display did not appear to be as competitive, raising concerns of added cost and decrease in ease-ofuse capability. A tablet computer solution would further add benefit through space savings within the PAC system by combining a separate computer and a separate display (with associated cabling) into a single unit. Based upon this research, it was determined that using a tablet computer instead of a separate computer and display would provide an effective and cost-efficient solution. Trade Study Method The following method was used to conduct the trade study (Utara, System Design and Integration, 2011): 1. Select a configuration item from PAC that is vital to system success 2. Identify requirements and functions that trace to the item 3. Identify alternatives 4. Identify selection criteria 5. Weight selection criteria (Pair-Wise Comparison) 6. Develop utility curves 7. Produce trade study matrix 8. Perform sensitivity analysis 9. Provide recommendations For this trade study, five alternatives and four selection criteria were identified. 2012_07_21_Karlow_Trade_Sudy_B 4/19

5 The primary requirements and functions that trace to the tablet computer component are shown below: Number Name Description REQ Pre-Loaded The system shall contain pre-loaded breakfast recipes (T=7)(O=31) Breakfasts REQ Pre-Loaded The system shall contain pre-loaded lunch recipes (T=7)(O=31) Lunches REQ Pre-Loaded Dinners Requirements and Functions The system shall contain pre-loaded dinner recipes (T=7)(O=31) These requirements are grandchildren to REQ.2.1 (The system shall be capable of making meals from pre-loaded recipes). REQ.2.1 is a composite requirement and Key Performance Parameter (KPP). The data storage capabilities of a tablet computer can be used to meet these requirements. The parent requirement for the three requirements mentioned above trace to FUNC Store Data. Number Name Description REQ Storing User- Provided Recipes The system shall be capable of storing user-provided recipes (T=30)(O=365) Similar to REQ , REQ , and REQ , REQ can be met through the data storage capabilities of a tablet computer. REQ traces to FUNC Save User-Provided Recipes, which traces via an N 2 diagram to FUNC Store Data. Number Name Description REQ Load Recipes from Personal Computer The system shall be capable of providing the user with the option to load recipes to PAC from their personal computer (T=via USB) (O=via internet) REQ can be met through the standard tablet computer features of USB and Wi-Fi capabilities. REQ traces to FUNC Retrieve Recipe from USB. REQ also traces to FUNC Retrieve Recipe from Internet, but this function has been deferred due to project descope. Number Name Description REQ Load Recipes Directly to PAC The system shall be capable of providing the user with the ability to use PAC directly to load user-provided recipes 2012_07_21_Karlow_Trade_Sudy_B 5/19

6 REQ can be met through the standard tablet computer feature of a touch-screen Human-Machine Interface (HMI). REQ traces to FUNC Receive Recipe Directly, which is decomposed by several functions that prompt the user to provide the necessary information data to input recipes directly to PAC. Number Name Description REQ Kitchen Modification The system shall be capable of incorporating into a home kitchen without major modification (T=removal of a few small cabinets and some existing appliances that PAC would provide the function for)(t=about as big as oven/range/microwave combination unit)(o=storable in cabinets) Although the sizes of other PAC components are unknown, a tablet computer's small size can contribute to meeting REQ As a constraint, REQ does not trace to a specific function. CORE traceability is completed by tracing this requirement to NO.FUNC (no function). Number Name Description REQ Fault Messages The system shall be capable of displaying fault messages to the user that provide a description of the fault A tablet computer can use its pre-loaded software features to display faults for the battery and USB/Wi-Fi features which can contribute to meeting REQ REQ traces to FUNC.8.4 Display Faults. Number Name Description REQ Simplicity of Operation The system shall be simple enough for an average 12 year old to operate (T=O) A competitive market and a younger generation of tablet computer users can lead to REQ being met by a tablet computer. REQ traces to FUNC.9.5 Interface with User, which is decomposed by FUNC Display Data to User, FUNC Receive Data from User, and FUNC Store Data. Alternative Pre-Selectors The highly competitive tablet computer market consists of dozens of possible alternatives available through internet-based shopping. Pre-selectors were used to help narrow the list of possible alternatives. Pre-Selector 1 Positive Customer Feedback 2012_07_21_Karlow_Trade_Sudy_B 6/19

7 The first pre-selector limited the available alternatives by eliminating any tablet computer that achieved less than 4 out of 5 in customer review scores on Additionally, any alternative that achieved a 4 out of 5 or greater, but had less than 200 customer reviews, was also eliminated. The intent of these two pre-selectors was to incorporate customer feedback satisfaction into the decision-making process, which relates to REQ Simplicity of Operation. Positive customer feedback ratings are important as incorporating a touch-screen computer to PAC that is cumbersome, excessively slow, or otherwise difficult to use would make the entire PAC system undesirable. Pre-Selector 2 Storage Size Preliminary estimates of PAC storage size requirements were calculated to eliminate additional tablet computer alternatives. The estimates are based upon work completed during Conceptual Design. Estimated Size (GB) Software Items Threshold Objective Control Software (11 GB each) Fault Storage Pre Loaded Recipes 50 MB each User Provided Recipes 50 MB each s Table 1: PAC Data Storage Size Estimates Based upon the above calculations pertaining to REQ , REQ , and REQ , REQ.2.2.4, and REQ , a tablet computer with 32 GB of storage would meet the objective requirements, thereby eliminating any alternatives with less than 32 GB of storage. Since tablet computers with 32 GB of storage are widely available, alternatives with greater than 32 GB were also eliminated as research showed higher storage capability increases cost. Pre-Selector 3 Screen Sizes (less than 7 inches) Although not a direct requirement, any alternative with a screen size less than 7 inches was eliminated, based on personal experience that an on-screen keyboard can be more difficult to use on screens less than 7 inches in diagonally-measured length. An on-screen keyboard impacts REQ while the small tablet size positively impacts REQ Pre-Selector 4 Screen Sizes (greater than 12 inches) with screen sizes greater than 12 inches were eliminated as a typical laptop computer keyboard is less than 12 inches measured diagonally, so alternatives with screen sizes between 7 and 12 inches would provide a usable on-screen keyboard to meet REQ and REQ A screen size greater than 12 inches would also take up additional space, negatively impacting REQ _07_21_Karlow_Trade_Sudy_B 7/19

8 Even after applying the pre-selectors, many tablet computer alternatives remained. In order to stay within project scope, five alternatives were selected. References for the specification data for these alternatives are provided in the References section of this report. Alternative 1 Apple ipad 3 The New ipad Screen size: 9.7 inches Screen Resolution: 2048x1536 Processor Speed: 1 GHz Operating Temperature Limit: 95 degrees F Cost: $600 Alternative 2 HP Touchpad Screen size: 9.7 inches Screen Resolution: 1024x768 Processor Speed: 1.2 GHz Operating Temperature Limit: 104 degrees F Cost: $291 Alternative 3 Tab 7.0 Screen size: 7 inches Screen Resolution: 1024x 600 Processor Speed: 1.2 GHz Operating Temperature Limit: 113 degrees F Cost: $438 Alternative 4 Sony SGPT112US Screen size: 9.4 inches Screen Resolution: 1280x800 Processor Speed: 1 GHz Operating Temperature Limit: 104 degrees F Cost: $488 Alternative 5 AT105-T1032 Screen size: 10.1 inches Screen Resolution: 1280x800 Processor Speed: 1 GHz Operating Temperature Limit: 104 degrees F Cost: $515 Several criteria were available to evaluate the alternatives per PAC requirements. Pre-selectors were used to eliminate criterion that was common to all 5 selected alternatives. Pre-Selector 1 Wi-Fi Selection Criteria Pre-Selectors 2012_07_21_Karlow_Trade_Sudy_B 8/19

9 For tablet computers, research demonstrated Wi-Fi internet capability to be a standard feature that all 5 alternatives have in common, per REQ Although FUNC Retrieve Recipe from Internet has been deferred to a future increment, including Wi-Fi capability for the first increment does not increase cost or negatively impact any other requirements Pre-Selector 2 RAM Each of the 5 alternatives has the same value for Random-Access Memory (RAM) of 1 GB so this was not used as a criteria. Although RAM does not have a direct requirement, the system will require minimal multi-tasking (such as operating the oven, range-top, or grill to pre-heat while ingredients are being prepared). 1 GB is sufficient to meet these functions. Pre-Selector 3 USB Each of the 5 alternatives has a Universal Serial Bus (USB) port or come with a data cable with a male USB interface. A female to female USB adapter may be required. Also, each alternative uses the USB for data transfer and power draw, so this needs to be noted during Conceptual Development. USB capability impacts REQ After applying the alternative pre-selectors and selection criteria pre-selectors, four selection criteria were used to evaluate the five options: Criteria 1 Screen Size The alternatives were evaluated for screen sizes where 7 inches is the threshold and 12 inches is the objective, as described above, per REQ and REQ Criteria 2 Screen Resolution The alternatives were evaluated for screen resolution, although not a direct requirement it does impact REQ as a quality display is inherently simpler to operate. 1024x600 was used as the threshold, with 2048x1536 as the objective, based upon the lowest and highest resolutions of the alternatives. Criteria 3 Processor Speed The alternatives were evaluated for processor speed, which impacts REQ as a quick display and computer is inherently simpler to operate. Personal experience sets 1 GHz as the threshold and 2 GHz as the objective. Criteria 4 Operating Temperature Limit Selection Criteria Due to close proximity to heating elements, the alternatives were evaluated for ability to operate in a high temperature environment. Although this does not impact a direct requirement, the tablet needs to be able to perform its functions while the heating elements producing heat during operation. 95 degrees 2012_07_21_Karlow_Trade_Sudy_B 9/19

10 Fahrenheit was set as the threshold and 113 degrees Fahrenheit as the objective, based upon the lowest and highest limits of the alternatives. It is assumed that the threshold value is based on a thermal analysis of PAC that demonstrates adequate insulation can be used to shield the tablet computer from high temperatures. Humidity exposure is also a concern for the tablet computer, but the use of a ducting system in PAC is designed to alleviate this concern. Therefore, a humidity operating limit was not used in this trade study. Additional Criteria 5 Cost If cost is a factor, $600 was set as the threshold and $291 the objective, based upon the lowest and highest costs of the alternatives. Pair-Wise Comparison Nth Root of Products of Weighting Factor Tablet Computer Trade Study: Pair Wise Comparison (Not including cost) Screen Size Resolution Speed Temperature Row Values Screen Size Resolution Speed Temperature (Nth Root / Sum of Nth Roots) N 4.00 N = Number of Criteria Sum of Nth Roots Table 2: Tablet Computer Trade Study Pair-Wise Comparison (not including cost) Nth Root of Products of Weighting Factor Tablet Computer Trade Study: Pair Wise Comparison (Including cost) Screen Size Resolution Speed Temperature Cost Row Values Screen Size Resolution Speed Temperature Cost (Nth Root / Sum of Nth Roots) N 5.00 N = Number of Criteria Sum of Nth Roots Table 3: Tablet Computer Trade Study Pair-Wise Comparison (including cost) Screen size is the most important criteria to meet the associated requirements listed above. Resolution is the second most important, close but not equal to screen size, in order to meet associated requirements. Speed is not as important, but still important. Lastly, temperature is the least important. Cost is not a requirement for this project but was included for additional information. Cost is always important, but the other criteria out rank it since there is no direct cost requirement. These comparisons are based off of the following scale (Utara, System Design and Integration, 2011): 2012_07_21_Karlow_Trade_Sudy_B 10/19

11 Table 4: Pair-Wise Comparison Scale Utility Curves Utility scores are based on the specification data collected for each alternative, with sources provided in the References section of this report. Figure 1: Screen Size Utility Curve 2012_07_21_Karlow_Trade_Sudy_B 11/19

12 Figure 2: Resolution Utility Curve Figure 3: Processor Speed Utility Curve 2012_07_21_Karlow_Trade_Sudy_B 12/19

13 Figure 4: Operating Temperature Utility Curve Figure 5: Cost Utility Curve Trade Study Matrix The utility scores were used to populate the comparison matrices. For each matrix, the highest scoring alternative is the most advantageous choice (reflected with a green highlight). The second place runnersup have the next highest score(s) and are highlighted in yellow. The lowest scoring alternatives are highlighted in red. 2012_07_21_Karlow_Trade_Sudy_B 13/19

14 Tablet Computer Trade Study: Comparison Matrix (Not including cost) Apple ipad 3 HP Touchpad Tab 7.0 Sony SGPT112US AT105 T1032 Screen Size Resolution Speed Temperature Table 5: Tablet Computer Trade Study Comparison Matrix (not including cost) Tablet Computer Trade Study: Comparison Matrix (Including cost) Apple ipad 3 HP Touchpad Tab 7.0 Sony SGPT112US AT105 T1032 Screen Size Resolution Speed Temperature Cost Table 6: Tablet Computer Trade Study Comparison Matrix (including cost) Without performing the sensitivity analysis, the Apple ipad 3 is the most advantageous choice. The is the next best alternative, with the HP, Samsung, and Sony models scoring the lowest. Sensitivity Analysis A sensitivity analysis was performed to identify critical parameters and examine any criteria bias. Each one of the criteria was zeroed-out and the matrices recalculated. 2012_07_21_Karlow_Trade_Sudy_B 14/19

15 Tablet Computer Trade Study: Comparison Matrix (Not including cost) Apple ipad 3 HP Touchpad Tab 7.0 Sony SGPT112US AT105 T1032 Screen Size Resolution Speed Temperature Table 7: Comparison Matrix (not including cost) Screen Size Sensitivity Tablet Computer Trade Study: Comparison Matrix (Not including cost) Apple ipad 3 HP Touchpad Tab 7.0 Sony SGPT112US AT105 T1032 Screen Size Resolution Speed Temperature Table 8: Comparison Matrix (not including cost) Resolution Sensitivity Tablet Computer Trade Study: Comparison Matrix (Not including cost) Apple ipad 3 HP Touchpad Tab 7.0 Sony SGPT112US AT105 T1032 Screen Size Resolution Speed Temperature Table 9: Comparison Matrix (not including cost) Speed Sensitivity 2012_07_21_Karlow_Trade_Sudy_B 15/19

16 Tablet Computer Trade Study: Comparison Matrix (Not including cost) Apple ipad 3 HP Touchpad Tab 7.0 Sony SGPT112US AT105 T1032 Screen Size Resolution Speed Temperature Table 10: Comparison Matrix (not including cost) Temperature Sensitivity Tablet Computer Trade Study: Comparison Matrix (Including cost) Apple ipad 3 HP Touchpad Tab 7.0 Sony SGPT112US AT105 T1032 Screen Size Resolution Speed Temperature Cost Table 11: Comparison Matrix (including cost) Screen Size Sensitivity Tablet Computer Trade Study: Comparison Matrix (Including cost) Apple ipad 3 HP Touchpad Tab 7.0 Sony SGPT112US AT105 T1032 Screen Size Resolution Speed Temperature Cost Table 12: Comparison Matrix (including cost) Resolution Sensitivity 2012_07_21_Karlow_Trade_Sudy_B 16/19

17 Tablet Computer Trade Study: Comparison Matrix (Including cost) Apple ipad 3 HP Touchpad Tab 7.0 Sony SGPT112US AT105 T1032 Screen Size Resolution Speed Temperature Cost Table 13: Comparison Matrix (including cost) Speed Sensitivity Tablet Computer Trade Study: Comparison Matrix (Not including cost) Apple ipad 3 HP Touchpad Tab 7.0 Sony SGPT112US AT105 T1032 Screen Size Resolution Speed Temperature Table 14: Comparison Matrix (including cost) Temperature Sensitivity Tablet Computer Trade Study: Comparison Matrix (Including cost) Apple ipad 3 HP Touchpad Tab 7.0 Sony SGPT112US AT105 T1032 Screen Size Resolution Speed Temperature Cost Table 15: Comparison Matrix (including cost) Cost Sensitivity Whether or not cost is included, the Apple ipad is still shown to be the most advantageous choice, except when screen resolution is not a factor. This is understandable considering the ipad s high-resolution display. Conclusions and Recommendations 2012_07_21_Karlow_Trade_Sudy_B 17/19

18 Based upon the results of the trade study as conducted, and factoring in all of the criteria together (screen size, screen resolution, processor speed, operating temperature, and cost), the Apple ipad 3 is recommended to be used in the PAC system. It is advised that additional research be performed, particularly through the use of focus groups, to further demonstrate that the ipad meets all associated requirements detailed in the Requirements and Functions section of this report. This is particularly important for REQ and REQ Additionally, it is recommend to first use the ipad in a prototype PAC, in order to evaluate the ipad in regards to durability and ease of cleaning. The use of a protective case could also be evaluated in regards to these criteria. These criteria were not included in this trade study due to lack of available data. The effectiveness of the PAC ducting system to divert humidity away from the tablet computer needs to be tested to ensure the ipad can survive the PAC environment. Additionally, the PAC system thermal analysis results need to be validated through testing to ensure the ipad s operating temperature limit is sufficient for the PAC environment. References Better Homes and Gardens Books. (2003). Better Homes and Gardens New Cookbook, 12th Edition. Des Moines, Iowa: Meredith Books. Utara, C. (2011, October 13). System Design and Integration. Retrieved May 06, 2012, from Johns Hopkins University Sakai: Utara, C. (2011, September 01). System Design and Integration. Retrieved July 19, 2012, from Johns Hopkins University Sakai: Data sources: 2012_07_21_Karlow_Trade_Sudy_B 18/19

19 Alternative Specification Data Sources: Screen size (in) Speed (GHz) Resolution Temp (operating) DegF Cost User Ratings RAM Screen size (in) Speed (GHz) Resolution Temp (operating) DegF Cost User Ratings RAM Screen size (in) Speed (GHz) Resolution Temp (operating) DegF Cost User Ratings RAM Power Source Screen size (in) Speed (GHz) Resolution Temp (operating) DegF Cost User Ratings RAM Screen size (in) Speed (GHz) Resolution Temp (operating) DegF Cost User Ratings RAM Apple ipad rd_s=auto sparkle&pf_rd_r=25289acc0eef424f8e5c&pf_rd_t=301&pf_rd_p= &pf_rd_i=ipad% app01 42?_dyncharset=ISO &_dynSessConf= &id=pcat17071&type=page&st=ipad+3&sc=Global&cp=1&nrp=15&sp=&qp=&list=n&iht=y&usc =All+Categories&ks=960 alias%3daps&field keywords=ipad+3 report.html HP Touchpad TouchPad 9 7 Inch Tablet Computer/dp/B0055D66V4/ref=sr_1_2?s=electronics&ie=UTF8&qid= &sr=1 2&keywords=hp+touchpad TouchPad 9 7 Inch Tablet Computer/dp/B0055D66V4/ref=sr_1_2?s=electronics&ie=UTF8&qid= &sr=1 2&keywords=hp+touchpad TouchPad 9 7 Inch Tablet Computer/dp/B0055D66V4/ref=sr_1_2?s=electronics&ie=UTF8&qid= &sr=1 2&keywords=hp+touchpad TouchPad 9 7 Inch Tablet Computer/dp/B0055D66V4/ref=sr_1_2?s=electronics&ie=UTF8&qid= &sr=1 2&keywords=hp+touchpad TouchPad 9 7 Inch Tablet Computer/dp/B0055D66V4/ref=sr_1_2?s=electronics&ie=UTF8&qid= &sr=1 2&keywords=hp+touchpad TouchPad 9 7 Inch Tablet Computer/dp/B0055D66V4/ref=sr_1_2?s=electronics&ie=UTF8&qid= &sr=1 2&keywords=hp+touchpad Tab Galaxy Plus Universal Remote/dp/tech data/b005n1333m/ref=de_a_smtd Galaxy Plus Universal Remote/dp/tech data/b005n1333m/ref=de_a_smtd Galaxy Plus Universal Remote/dp/tech data/b005n1333m/ref=de_a_smtd Galaxy Plus Universal Remote/dp/tech data/b005n1333m/ref=de_a_smtd Galaxy Plus Universal Remote/dp/tech data/b005n1333m/ref=de_a_smtd Galaxy Plus Universal Remote/dp/tech data/b005n1333m/ref=de_a_smtd Sony SGPT112US 1&partNumber=SGPT112US/S&SR=sony_search_seo&SQS=SGPT112US SGPT112US Wi Fi Tablet 32GB/dp/tech data/b005fxykoe/ref=de_a_smtd 1&partNumber=SGPT112US/S&SR=sony_search_seo&SQS=SGPT112US Estimated at 104 DegF (average of the other four alternatives) no data available SGPT112US Wi Fi Tablet 32GB/dp/tech data/b005fxykoe/ref=de_a_smtd SGPT112US Wi Fi Tablet 32GB/dp/tech data/b005fxykoe/ref=de_a_smtd 1&partNumber=SGPT112US/S&SR=sony_search_seo&SQS=SGPT112US AT105 T Thrive 10 1 Inch Android AT105 T1032/dp/tech data/b0052p6um0/ref=de_a_smtd Thrive 10 1 Inch Android AT105 T1032/dp/tech data/b0052p6um0/ref=de_a_smtd Thrive 10 1 Inch Android AT105 T1032/dp/tech data/b0052p6um0/ref=de_a_smtd T32.pdf Thrive 10 1 Inch Android AT105 T1032/dp/tech data/b0052p6um0/ref=de_a_smtd Thrive 10 1 Inch Android AT105 T1032/dp/tech data/b0052p6um0/ref=de_a_smtd _07_21_Karlow_Trade_Sudy_B 19/19