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Project management. Organising, planning and scheduling software projects Objectives To introduce software project management and to describe its distinctive characteristics To discuss project planning and the planning process
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Project management • Organising, planning and scheduling software projects • Objectives • To introduce software project management and to describe its distinctive characteristics • To discuss project planning and the planning process • To show how graphical schedule representations are used by project management • To discuss the notion of risks and the risk management process
Terminology • Milestones • Have a duration of zero • Identify critical points in your schedule • Shown as inverted triangle or a diamond • Often used at “review” or “delivery” times • Or at end or beginning of phases • Ex: Software Requirements Review (SRR) • Ex: User Sign-off • Can be tied to contract terms
Terminology Example Milestones
Waterfall Model: Analysis Phase I1:Open A.I1:Open I2:Open I3:Open A.I2:Open SD.I1:Open Analysis Analysis SD.I3:Open SD.I2:Open
Waterfall Model: Design Phase I1:Closed A.I1:Open I2:Closed I3:Open A.I2:Open SD.I1:Open Analysis Analysis SD.I3:Open SD.I2:Open Design
Waterfall Model: Implementation Phase I1:Closed A.I1:Closed I2:Closed I3:Closed A.I2:Closed SD.I1:Open Analysis SD.I3:Open SD.I2:Open Design Implementation
Waterfall Model: Project is Done I1:Closed A.I1:Closed I2:Closed I3:Closed A.I2:Closed SD.I1:Open Analysis SD.I3:Open SD.I2:Open Design Implementation
Issue-Based Model: Analysis Phase I1:Open A.I1:Open I2:Open I3:Open A.I2:Open Analysis:80% SD.I1:Open SD.I3:Open SD.I2:Open Design: 10% Implemen-tation: 10%
Issue-Based Model: Design Phase I1:Closed A.I1:Open I2:Closed I3:Open A.I2:Open Analysis:40% SD.I1:Open SD.I3:Open SD.I2:Open Design: 60% Implemen-tation: 0%
Issue-Based Model: Implementation Phase I1:Open A.I1:Open I2:Closed I3:Closed A.I2:Closed Analysis:10% SD.I1:Open SD.I3:Open SD.I2:Cosed Design: 10% Implemen-tation: 60%
Issue-Based Model: Project is Done I1:Closed A.I1:Closed I2:Closed I3:Closed A.I2:Closed Analysis:0% SD.I1:Closed SD.I3:Closed SD.I2:Closed Design: 0% Implemen-tation: 0%
Software project management • Concerned with activities involved in ensuring that software is delivered • on time • within the budget • in accordance with the requirements • Project management is needed because software development is always subject to budget and schedule constraints • Set by the development organisation or the customer
Project staffing • May not be possible to appoint the ideal people to work on a project • Managers have to work within these constraints • especially when (as is currently the case) there is an international shortage of skilled IT staff
Project planning • Probably the most time-consuming project management activity • Continuous activity from initial concept through to system delivery • Plans must be regularly revised as new information becomes available • Beware of grumbling developers • Various different types of plan may be developed to support the main software project plan that is concerned with schedule and budget
Activity organization • Activities in a project should be organised to produce tangible outputs for management to judge progress • Milestones are the end-point of a process activity • Deliverables are project results delivered to customers
Project scheduling • Split project into tasks and estimate time and resources required to complete each task • Organize tasks concurrently to make optimal use of workforce • Minimize task dependencies to avoid delays caused by one task waiting for another to complete • Dependent on project managers’ intuition and experience
PERT • Program Evaluation and Review Technique • Based on idea that estimates are uncertain • Therefore uses duration ranges • And the probability of falling to a given range • Uses an “expected value” (or weighted average) to determine durations • Use the following methods to calculate the expected durations, then use as input to your network diagram
PERT • Start with 3 estimates • Optimistic • Would likely occur 1 time in 20 • Most likely • Modal value of the distribution • Pessimistic • Would be exceeded only one time in 20
PERT Formula • Combined to estimate a task duration
PERT Formula • Confidence Interval can be determined • Based on a standard deviation of the expected time • Using a bell curve (normal distribution) • For the whole critical path use
PERT Example • Confidence interval for P2 is 4 times wider than P1 for a given probability • Ex: 68% probability of 9.7 to 11.7 days (P1) vs. 9.5-13.5 days (P2)
PERT • Advantages • Accounts for uncertainty • Disadvantages • Time and labor intensive • Assumption of unlimited resources is big issue • Lack of functional ownership of estimates • Mostly only used on large, complex project • Get PERT software to calculate it for you
The risk management process • Risk identification – Identify project, product and business risks • Risk analysis – Assess the likelihood and consequences of risks • Risk planning – Draw up plans to avoid/minimise risk effects • Risk monitoring – Monitor the risks throughout the project
Risk identification • Technology risks • People risks • Organisational risks • Requirements risks • Estimation risks
Risk analysis • Assess probability and seriousness of each risk • Probability may be • very low • low • moderate • high • very high • Risk effects might be • catastrophic • serious • tolerable • insignificant
Risk planning • Consider each risk and develop a strategy to manage that risk • Avoidance strategies • The probability that the risk will arise is reduced • Minimisation strategies • The impact of the risk on the project or product will be reduced • Contingency plans • If the risk arises, contingency plans are plans to deal with that risk