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Software Engineering Process II

Software Engineering Process II

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Software Engineering Process II

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  1. Software Engineering Process II Development Plan INFO 637 Glenn Booker Lecture #4

  2. Need to Plan • We need to plan our effort carefully, to help ensure that: • Everyone knows what to do and when • We know if we’re going off schedule • We can improve the accuracy of our predictions • Detailed planning helps make some of our inaccuracies counterbalance each other • Results in more accurate overall estimates Lecture #4

  3. Plan(ned) Hours • Each task is assigned a planned number of hours for its completion (Plan Hours), based on the estimation methods discussed in the PSP • The sum of Plan Hours for all tasks is the total effort needed for the project, in staff-hours (Total Plan Hours) Lecture #4

  4. Plan Value • Each task is also assigned a Plan Value (PV), which is the percent of the project’s value assigned to completing that task • The sum of Plan Value for all tasks in the project is, by definition, 100% • If all tasks are equal significance by effort, PV = (Plan Hours) * 100 / (Total Plan Hours) Lecture #4

  5. Earned Value • As tasks are completely finished, they earn Earned Value (EV) in the amount of their Plan Value • Hence at any time, the total EV earned is the sum of PV for all tasks which have been completed Lecture #4

  6. How Detailed to Plan? • Tasks should be broken down to under ten hours per person per task • For a full project, you generally don’t want to micromanage to tasks under a work-day, because then you’ll spend more time planning than working Lecture #4

  7. Where Record Tasks? • The overall project, and small programming tasks, can be planned on a SUMP form • Unplanned tasks (including startup for the project) can be identified as M&M (Management and Miscellaneous) tasks • M&M is typically 5-10% of the first cycle • Quality plans go on a SUMQ form Lecture #4

  8. Software Estimates • Use the same techniques used for the PSP • Sizes of parts and assemblies, ranging from smallest to largest, are called: • Modules (assemblies of objects) • Components (assemblies of modules) • Products (assemblies of components) • System (assemblies of products) Lecture #4

  9. TSPi Planning Process • Conceptual design was created in the strategy phase • Initial estimates of parts for each cycle were also developed in the strategy phase (STRAT form) Lecture #4

  10. TSPi Planning Process • Now use SUMS form to list the components to be developed in the first cycle • Also on the SUMS form, identify test plans and requirements specifications which apply to these components Lecture #4

  11. TSPi Planning Process • Use TASK and SCHEDULE forms to identify how long each component will take to create • Include time for individual effort each week, and team effort as well • Blend to provide TASK and SCHEDULE for entire team • Calculate PV and expected completion date for each task Lecture #4

  12. TSPi Planning Process • Make the quality plan, using SUMQ form (discussed later) • Copy TASK and SCHEDULE for each person • Personalize these by deleting tasks others will perform • Determine PV and estimated completion for each personal task Lecture #4

  13. TSPi Planning Process • Review the TASK and SCHEDULE forms for each person, and balance the workload • Adjust tasks and responsibilities as needed to make the schedule fair to everyone • Use the adjusted individual plans to regenerate the overall team TASK and SCHEDULE, plus the SUMP and SUMQ • Give these to all team members and instructor Lecture #4

  14. TSPi Support Tool • The TSPi Support Tool can be used to help support this process, but it doesn’t fully automate the process • If not using the Tool, most teams discuss and balance their workload before committing it to the forms, to avoid revising the individual plans, and then regenerating the team plans Lecture #4

  15. Development Plan Script PLAN1 p. 75 • Based on the conceptual design • Identify specific products to be produced, and estimate their sizes • Record STRAT data in SUMS • Produce task plan using TASK form • Produce team’s schedule plan using SCHEDULE form, including expected weekly hours per person Lecture #4

  16. Development Plan Script PLAN1 • Produce the quality plan using estimated SUMP and SUMQ plans • Break out individual plans based on the team TASK and SCHEDULE plans • Balance workload, then reconsolidate the team TASK and SCHEDULE plans • Send TASK, SCHEDULE, SUMS, SUMP, and SUMQ to team members and instructor Lecture #4

  17. Tracking Work • Record your time in the time recording log (LOGT) • This helps update your personal TASK and SCHEDULE forms • When a task is completed, enter the week in the TASK form • This will feed the Earned Value for that week Lecture #4

  18. Tracking Work • At the end of each work week, generate the updated TASK and SCHEDULE to show the time and EV status of your work • Enter these on the WEEK form, and give to your planning manager • Enter defects on the defect recording log (LOGD) • These feed the SUMP form for each assembly Lecture #4

  19. Tracking Work • Note that inspection defects (INS) do not automatically show up; the product owner needs to enter each inspection defect on form LOGD as well • Once a component has been developed, enter its size in SUMS for that part • Includes documentation size, not just code Lecture #4

  20. Tracking Work • Update SUMP to track the time, size, and defect data for each engineer • A separate SUMP should be maintained for each assembly, and each phase • Generate the SUMQ form for each assembly, with time, size, and defect data • Generate team level TASK & SCHEDULE, and assembly-level SUMP and SUMQ Lecture #4

  21. Tracking Work • Each person reports to the team weekly using the WEEK script; and the team reports to the instructor using the same form Lecture #4

  22. Quality Plan • The quality plan (SUMQ) is outlined on pages 88-89 • It is a summary of the quality results for the project to date, comparing the quality goals with the actual results as they become available • Description of each SUMQ section follows Lecture #4

  23. Quality Plan • Summary section has the overall team productivity (LOC/hour), and the percent of reuse and new reuse (if any) • Percent Defect-Free (PDF) section describes the percent of components which had no defects, by life cycle phase • Defects/page describes documentation quality Lecture #4

  24. Quality Plan • Defects/KLOC describes the total number of defects which were found during development • Defect Ratios compare the defect rates for different activities • Development time ratios (%) compare the amount of time spent in phases to their review activities Lecture #4

  25. Quality Plan • A/FR is the Appraisal to Failure Ratio; the ratio of time spent in reviews and inspections to the time spent in failure detection activities (compile, test) • Want A/FR > 2 for small programs, >1 if large • Review Rates and Inspection Rates measure how fast reviews and inspections are performed Lecture #4

  26. Quality Plan • Defect injection and removal rates (Defects/Hr.) measure how quickly defects were made and discovered during each life cycle phase or inspection • Phase Yield is the percent of defects entering the phase which were removed • Process Yield is the percent of defects removed before entering a phase Lecture #4

  27. Quality Plan • The quality plan is heavily dependent on having sound data input • Hence the data recorded for every task and every defect must be as accurate as possible, or the final results will quickly become gibberish! Lecture #4