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Problem Areas with the Project. Class Descriptions were non existent Use case descriptions were terse or non existent Verification methods were wrong Equal effort within teams. Grading Example. Change Was 11%. Possible # of points. Penalty points. Grades. 88% 104% 88% 92% 86% 95%
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Problem Areas with the Project • Class Descriptions were non existent • Use case descriptions were terse or non existent • Verification methods were wrong • Equal effort within teams
GradingExample Change Was 11% Possible # of points Penalty points
Grades 88% 104% 88% 92% 86% 95% 0% - not started 75% - late Average was 89.7 ( not counting the 0%)
Class Descriptions • Class Descriptions should introduce the reader to the object class • It should be a paragraph • It should denote • If it is a hardware, software, person, parameter … etc • if it is a commercial product • IF it is temporary, permanent • Part of another class (aggregation composition) • Anything else that you know about the class/ object
Use Case Descriptions • Use case descriptions should describe what the use case is doing and who is doing it. • It should: • Indicate the goal of the Use Case. e.g. Indicate the scope and duration of the use case. This use case creates a valid order based on customer provided information. It is executed whenever the customer indicates a desire to finalize the order. Since the information is private, this session is done in a secure mode. The entire process of entering an order is temporary and is aborted if the customer does not respond within a proper time frame. All the order and customer information derived from this use case is stored in a secure server. The process ends whenever all the information is collected and the customer indicates finished, the customer cancels the order, or the process times out from lack of activity.
Requirements Verification Methods • Most requirements should be tested. • Test : The system is run in a particular sequence to show the successful implementation of the requirement. The test must match the documented expected test results. • Demonstrate : While similar to test the requirement is shown to be correct. The result must be obvious. ( visible, audible… ) It must be difficult to attach a test result. • Inspect : Static characteristic shown to the customer. • Analyze : Some type of analysis is performed and documented. This could be a spreadsheet, simulation… the documentation must be captured in a formal paper.
Equal Effort Among Members Within Teams • Next Time • I will ask each member of a team to rate the other members within the team • This will affect the team member’s individual grades.
Homework : Due November 3rd • Divide up your project classes among team members. Create class descriptions. • Divide up your project use cases among team members. Create / re-do use case descriptions. • Divide up requirements among team members • Send them to me ( subject: Project updates) • Add them to your project (don’t send them to me) No class on October 27, 2003
Trade Study Purpose Purpose : Trade study is used to objectively choose between multiple acceptable candidate solutions Halloween Party
Trade Study Description • select the best solution to meet an identified problem within defined constraints • Defines a structured analytic framework for evaluating a set of alternative concepts, designs, or components • Conducted concurrently with other requirements development and design activities • Range from an informal comparison of alternatives to major efforts using sophisticated computer tools for simulation and cost estimation. ? What Costume should I wear? Who should I go with?
Trade Study Process • Define Objectives • Identify Candidates • Establish Evaluation Criteria • Conduct analysis • Document Results • Review
Stakeholders can be: • Other business disciplines • Customer • Corporate • Yourself • Etc. Define Objective for Analysis • Define the objective and purpose of the analysis • Determine scope of trade study • Determine level of supportinganalyses • Determine amount of review and approvals needed • Determine level of documentation • Obtain approval with stakeholders of the objective and ensure that there is agreement on the purpose and scope of the analysis
Define Objective for Analysis - Example • Objective: • Decide where best to eat lunch on a typical workday. • Purpose: • Get the best value for lunch • Scope: • Where, how, what, how much, with whom Be sure to get approval of the purpose and scope of the objective from stakeholders.
Establish Evaluation Criteria and Weights • Establish an evaluation criteria and weighting for considering system design alternatives that includes, as a minimum, cost drivers, total ownership and life cycle cost, complexity, technical limitations, environmental impact, system expansion, growth, and risk. • Establish an evaluation criteria and weighting that is a tailored version of the standard criteria and weighting • Review the evaluation criteria to ensure that they are consistent with the range of alternatives. Obtain agreement of decision maker on evaluation criteria and weights
Weighting Tailor criteria and weighting as appropriate. Ensure weighting is normalized, and grading uses the same scale (good=low) and range across criteria.
Establish Evaluation Criteria and Weights - Example weights criteria Most Trade Studies will have items related to Cost, Schedule, and Performance and Risk as part of their evaluation criteria. Refer to SYSENG-100 Appendix E
Establish Evaluation Criteria and Weights - Example Grades for “Time Required” 0 to 15 minutes Very low impact (1) 15 to 30 minutes Low impact (2) 30 to 45 minutes Medium impact (3) 45 to 60 minutes High impact (4) Over 60 minutes Very high impact (5)
Identify Candidate Alternatives • Generate alternative candidate solutions. • Reject unfeasible alternatives • Document rejected candidates • Feedback loop Option 1 Option 2 . . . Option 3 Option n
Identify Candidate Alternatives - Example alternatives For larger trade studies, it is a good idea to have a formal review of alternatives and criteria before proceeding with the analysis.
Conduct Analysis of Alternatives • Develop timelines scenarios for system operation and user interaction for each system design alternative. • Allocate key requirements to the hardware and software components for each of the design alternative as a part of the analysis. • Analyze all candidate alternatives that have been identified. • Analyze the alternatives using a structured decision making technique that is appropriate for the analysis. • Use the evaluation criteria and weighting to select the recommended alternative (see example). • Determine the alternative representing the “Best Value” for projects that have a CAIV requirement. • Evaluate the failure conditions associated with each of the alternatives. • Perform a sensitivity analysis to determine if any factors inordinately dominate the selection outcome
Conduct Analysis of Alternatives - Example 1 Example: Timeline Analysis Use analysis techniques such as timeline analysis, CAIV, analysis of possible failure conditions, etc.
Conduct Analysis of Alternatives - Example 2 Another Example: Data Gathering McDonald’s Web Site
Conduct Analysis of Alternatives - Example 3 Apply weights to grades to find optimum alternative Multiply weight times grade, and sum across all criteria, i.e. .3(1)+.3(1)+.3(1)+.1(3) =1.2
Document Analysis Results The report contains the following: • Document the rationale for the analysis decisions. • Document the decision making technique used for the analysis and the rationale for its selection. • Document the rationale for the selection of the evaluation criteria and weighting for the analysis. • Document alternatives considered and the rationale for not selecting them as the recommended alternative. It is recommend to produce the document incrementally in parallel with the process
Document Analysis Results – Style-guide Introduction Introduce the subject of your analysis. Who are the users / stakeholders… Requirements, Constraints, and Assumptions What are the Big requirements and constraints. If you are not sure about something or can’t prove something list your assumptions. Trade Study Objective What are you trying to accomplish by doing this trade study Definition of Alternatives Talk about the alternatives. Provide a narrative about each one of them with separate headings. Talk about the features of each. Evaluation Criteria, Grading, Weighting and Scoring List and description of evaluation criteria. Create a table of grading, weighting and scoring. This is where the spreadsheet goes. Conclusions and Recommendations Describe the results and pay particular attention to any conclusions that aren’t obvious
Document Analysis Results - Example Style-guide Trade Study Report
Review/Approve Analysis Report • Review the candidate alternatives to ensure that the appropriate alternatives have been analyzed. If all appropriate alternatives have not been analyzed, then the analysis of alternatives needs to be continued • Review the assumptions to ensure that they are reasonable and valid for the alternatives being considered. • Review the selected alternative to ensure it is the best solution based on the evaluation criteria and weighting.
When to Conduct a Trade Study • Trade Studies are usually conducted to help understand competing solutions and to select the most optimal solution. Trade Studies are usually conducted for items significantly impacting: • Cost • Schedule • High Risk Items • Performance Objectives • Architectural Design