©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 1 Chapter 5 Project Management “…a huge topic.” See Part 6, “Managing People”.

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 2 Project management l Organizing, planning and scheduling software projects

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 3 Objectives l To introduce software project management and to describe its distinctive characteristics. l To discuss project planning and the planning process. l To show how graphical schedule representations are used by project management. l To discuss the notion of risks and the risk management process.

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 4 Topics covered l Management activities l Project planning l Project scheduling l Risk management

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 5 l Concerned with activities involved in ensuring that software is delivered on time, within budget and in accordance with the requirements of the organizations developing and procuring the software. l Project management is needed because software development is always subject to budget and schedule constraints that are set by the organization developing the software. Software project management

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 6 l The product is intangible. l The product is uniquely flexible. l Software engineering is not recognized as an engineering discipline with the same status as mechanical, electrical engineering, etc. l The software development process is not standardized. l Many software projects are “one-off” projects. Software management distinctions one-of-a-kind

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 7 l Proposal writing (to fund new projects) l Project planning and scheduling (focus of this Chap) l Project costing and preparing bids (Chap 26) l Project monitoring and reviews l Personnel selection and evaluation (Chap 25) l Report writing and presentations l Attending lots and lots of meetings! IBM Santa Teresa study, etc., … Management activities

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 8 l These activities are not peculiar to software management. l Many techniques of engineering project management are equally applicable to software project management. l Technically complex engineering systems tend to suffer from most of the same problems as software systems. Management commonalities

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 9 Project staffing l May not be possible to appoint the ideal people to work on a project… Project budget may not allow for use of highly-paid staff. Those with appropriate skills / experience may not be available. An organization may wish to develop employee skills by assigning inexperienced staff. l Managers have to work within these constraints especially when there is a shortage of skilled IT staff.

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 10 Project planning l Probably the most time-consuming project management activity (or at least it should be). l Continuous activity from initial concept to system delivery. Plans must be regularly revised as new information becomes available. l Different types of sub-plans may be developed to support a main software project plan concerned with overall schedule and budget.

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 11 Types of project sub-plans (QA)

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 12 Project planning “The plan is nothing – the planning is everything.” – Dwight Eisenhower, on the D-Day invasion plan (a bit of dramatic overstatement to make a point…)

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 13 Project planning process - not idle time… cancelled loop

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 14 The project plan l The project plan sets out: The resources available to the project; The work breakdown; A schedule for the work.

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 15 Project plan document structure l Introduction (goals, constraints, etc.) l Project organization l Risk analysis l Hardware and software resource requirements l Work breakdown l Project schedule l Monitoring and reporting mechanisms

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 16 Activity organization l Activities in a project should be associated with tangible outputs for management to judge progress (i.e., to provide process visibility) l Milestones are the unequivocal end-points of process activities. e.g., “DR1 complete” versus “90% of design complete”

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 17 Activity organization l Deliverables are project results delivered to customers. (There are also internal “deliverables”.) l The waterfall model allows for the straightforward definition of milestones (“a deliverable oriented model”). l Deliverables are always milestones, but milestones are not necessarily deliverables.

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 18 Milestones in the RE process

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 19 Project scheduling l Split project into tasks and estimate time and resources required to complete each. l Tasks should not be too small or too large – they should last on the order of weeks for projects lasting months. (“Models should be as simple as possible, but no simpler.”)

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 20 Project scheduling l Organize tasks as concurrent activities to make optimal use of workforce. l Minimize task dependencies to avoid potential delays. l Dependent on project managers’ intuition and experience. (Good management is not a science.)

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 21 The project scheduling process Review Progress

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 22 Scheduling problems l Estimating the difficulty of problems, and hence the cost of developing solutions, is hard. l Progress is generally not proportional to the number of people working on a task. l Adding people to a late project can make it later (due to coordination overhead). (F. Brooks, The Mythical Man-Month) l The unexpected always happens. Always allow for different contingencies in planning. (a.k.a. “Murphy’s Law”)

TIMETIME PEOPLE fewmany less more

TIMETIME PEOPLE fewmany less more What if time and people were perfectly interchangeable?

TIMETIME PEOPLE fewmany less more What if time and people were perfectly interchangeable? 1 person/12 months 12 persons/1 month

TIMETIME PEOPLE fewmany less more 1 person/12 months What if time and people were perfectly interchangeable? 12 persons/1 month

TIMETIME PEOPLE fewmany less more K = time X people

TIMETIME PEOPLE fewmany less more Stuffing Envelopes

TIMETIME PEOPLE fewmany less more Having a baby Stuffing Envelopes

TIMETIME PEOPLE fewmany less more Software Development Having a baby Stuffing Envelopes

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 31 Bar charts and activity networks l Graphical notations are often used to illustrate project schedules. l Activity charts (a.k.a. PERT* charts) show task dependencies, durations, and the critical path. l Bar charts (a.k.a. GANTT charts) generally show resource (e.g., people) assignments and calendar time. * Program Evaluation and Review Technique

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 32 Task durations and dependencies

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 33 Activity network |CP|=55

How much potential “slack time” is associated with Task J? If J is on the Critical Path, CP, then 0 Else |CP| - |JL| where JL is the longest path containing J

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 35 Consider Task T4… |CP|=55

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 36 Activity timeline duration potential slack time: = 20 days

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 37 Staff allocation (Gantt) Chart

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 38 Risk management l Risk management is concerned with identifying risks and drawing up plans to minimize their effect on a project.

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 39 Risk management (cont’d) l A risk exists when there is a probability that some adverse circumstance will occur. Project risks affect schedule or resources. Product risks affect the quality or performance of the software being developed. Business risks affect the organization developing or procuring the software. (Taxonomy based on Effect)

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 40 Software risks

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 41 The risk management process l Risk identification – identify project, product and business risks l Risk analysis – assess the likelihood and consequences of these risks l Risk planning – draw up plans to avoid or minimise the effects of the risk l Risk monitoring – monitor the risks throughout the project We consider each of these activities in turn...

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 42 The risk management process

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 43 Risk identification l Types –Technology risks –People risks –Organizational risks –Tools risks –Requirements risks –Estimation risks (Taxonomy based on Source)

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 44 Risks and risk types

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 45 Risk analysis l Assess probability and seriousness of each risk. l Probability may be very low, low, moderate, high or very high. l Risk effects might be catastrophic, serious, tolerable or insignificant.

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 46 Risk analysis

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 47 Risk planning l Consider each risk and develop a strategy to manage that risk. l Avoidance strategies – the probability that the risk will arise is reduced. l Minimisation strategies – the impact of the risk on the project or product is reduced. l Contingency plans – if the risk arises, contingency plans are plans to deal with that risk. (to effect the minimisation strategy)

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 48 Risk management strategies

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 49 Risk monitoring l Assess each identified risk regularly to decide whether or not it is becoming less or more probable. l Also assess whether the effects of the risk have changed. l Each key risk should be discussed at management progress meetings.

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 50 Risk factors (  warning signs)

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 51 Key points l Good project management is essential for project success. (Necessary, but not sufficient…) l The intangible nature of software causes problems for management. l Managers have diverse roles, but their most significant activities are planning, estimating, and scheduling. l Planning and estimating are iterative processes which continue throughout the course of a project.

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 52 l A project milestone is a predictable state where some formal report of progress is presented to management. l Risks may be project risks, product risks or business risks. (and: technology, people, organisational, tools, requirements, or estimation risks) l Risk management is concerned with identifying risks which may affect the project, and planning to ensure that these risks do not develop into major threats. Key points (cont’d)

©Ian Sommerville 2000Software Engineering. Chapter 5 Slide 53 Chapter 5 Project Management “…a huge topic.” See Part 6, “Managing People”.