ch5 (2).pdf

Project Management ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 1  Objectives  To explain the main tasks undertaken by project managers  To introduce software project management an...

Project Management ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 1  Objectives  To explain the main tasks undertaken by project managers  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 ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 2  Topics covered  Management Activities  Project Planning  Project Scheduling  Risk Management ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 3  Software project management  Concerned with activities involved in ensuring that software is delivered on time and on schedule and in accordance with the requirements of the organisations developing and procuring the software.  Project management is needed because software development is always subject to budget and schedule constraints that are set by the organisation developing the software. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 4  Software management distinctions  The product is intangible.  The product is uniquely flexible.  Software engineering is not recognized as an engineering discipline with the sane status as mechanical, electrical engineering, etc.  The software development process is not standardised.  Many software projects are 'one-off' projects. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 5  Management activities  Proposal Writing.  Project Planning and Scheduling.  Project Costing.  Project Monitoring and Reviews.  Personnel Selection and Evaluation.  Report Writing and Presentations. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 6  Management commonalities  These activities are not peculiar to software management.  Many techniques of engineering project management are equally applicable to software project management.  Technically complex engineering systems tend to suffer from the same problems as software systems. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 7  Project staffing  May not be possible to appoint the ideal people to work on a project Project budget may not allow for the use of highly-paid staff; Staff with the appropriate experience may not be available; An organisation may wish to develop employee skills on a software project.  Managers have to work within these constraints especially when there are shortages of trained staff. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 8  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.  Various different types of plan may be developed to support the main software project plan that is concerned with schedule and budget. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 9  Types of project plan Plan Description Quality plan Describes the quality procedures and standards that will be used in a project. See Chapter 27. Validation plan Describes the approach, resources and schedule used for system validation. See Chapter 22. Configuration Describes the configuration management procedures and manageme nt plan structures to be used. See Chapter 29. Maintenance plan Predicts the maintenance requirements of the system, maintenance costs and effort required. See Chapter 21. Staff development Describes how the skills and experience of the project team plan. members will be developed. See Chapter 25. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 10  Project planning process Establish the project constraints Make initial assessments of the project parameters Define project milestones and deliverables while project has not been completed or cancelled loop Draw up project schedule Initiate activities according to schedule Wait ( for a while ) Review project progress Revise estimates of project parameters Update the project schedule Re-negotiate project constraints and deliverables if ( problems arise ) then Initiate technical review and possible revision end if end loop ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 11  The project plan  The project plan sets out: The resources available to the project; The work breakdown; A schedule for the work. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 12  Project plan structure  Introduction.  Project organisation.  Risk analysis.  Hardware and software resource requirements.  Work breakdown.  Project schedule.  Monitoring and reporting mechanisms. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 13  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.  The waterfall process allows for the straightforward definition of progress milestones. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 14  Milestones in the RE process ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 15  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. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 16  The project scheduling process ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 17  Scheduling problems  Estimating the difficulty of problems and hence the cost of developing a solution is hard.  Productivity is not proportional to the number of people working on a task.  Adding people to a late project makes it later because of communication overheads.  The unexpected always happens. Always allow contingency in planning. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 18  Bar charts and activity networks  Graphical notations used to illustrate the project schedule.  Show project breakdown into tasks. Tasks should not be too small. They should take about a week or two.  Activity charts show task dependencies and the the critical path.  Bar charts show schedule against calendar time. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 19  Task durations and dependencies Activity Duration (da ys) Dependencies T1 8 T2 15 T3 15 T1 (M1) T4 10 T5 10 T2, T4 (M2) T6 5 T1, T2 (M3) T7 20 T1 (M1) T8 25 T4 (M5) T9 15 T3, T6 (M4) T10 15 T5, T7 (M7) T11 7 T9 (M6) T12 10 T11 (M8) ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 20  Activity network 1 4 /7 /0 3 15 da y s 15 da y s M1 T3 8 day s T9 T1 5 day s 4 /8/03 2 5 /8/03 2 5 /7 /0 3 4 /7 /0 3 T6 M4 M6 M3 start 2 0 day s 7 day s 15 day s T7 T 11 T2 25 /7 /0 3 11 /8/03 5 /9/03 10 da y s 10 day s M2 M7 M8 T4 T5 15 da y s T 10 10 da ys 1 8 /7 /0 3 T 12 M5 2 5 day s T8 Finish 19 /9/03 ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 21  Activity timeline 4 /7 11 /7 18 /7 2 5 /7 1 /8 8 /8 1 5 /8 22 /8 2 9 /8 5 /9 12 /9 1 9 /9 Start T4 T1 T2 M1 T7 T3 M5 T8 M3 M2 T6 T5 M4 T9 M7 T 10 M6 T 11 M8 T 12 Finish ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 22  Staff allocation 4 /7 1 1 /7 18 /7 2 5 /7 1 /8 8 /8 15 /8 2 2 /8 2 9 /8 5 /9 1 2 /9 19 /9 Fred T4 T8 T 11 T 12 Jane T1 T3 T9 An ne T2 T6 T 10 Jim T7 M ary T5 ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 23  Risk management  Risk management is concerned with identifying risks and drawing up plans to minimise their effect on a project.  A risk 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 organisation developing or procuring the software. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 24  Software risks Risk Affects Description Staff turnover Project Experienced staff will leave the project before it is finished. Management change Project There will be a change of organisational management with different priorities. Hardware unavailability Project Hardware that is essential for the project will not be delivered on schedule. Requirements change Project and There will be a larger numb er of changes to the product requirements than anticipated. Specification delays Project and Specifications of essential interfaces are not available on product schedule Size underestimate Project and The size of the system has been underestimated. product CASE t ool under- Product CASE t ools which support the project do not perform as performance anticipated Technology change Business The underlying technology on which the system is b uilt is superseded by new technology. Product comp etition Business A competitive product is marketed before the system is completed. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 25  The risk management process  Risk Identification Identify project, product and business risks;  Risk Analysis Assess the likelihood and consequences of these risks;  Risk Planning Draw up plans to avoid or minimise the effects of the risk;  Risk Monitoring Monitor the risks throughout the project; ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 26  The risk management process ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 27  Risk identification  Technology risks.  People risks.  Organisational risks.  Requirements risks.  Estimation risks. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 28  Risks and risk types Risk type Possibl e risks Techno logy The da tabase used in the system canno t process as many transactions per second as exp ected. Software componen ts that shou ld be reus ed contain defects that limit their func tiona lity. People It is im possible to recruit staff wit h the skill s required. Key staff are ill and unava ilable at criti cal tim es. Requi red training for staff is not availa ble. Organ isationa l The o rgan isation is restructured so that diff erent manag ement are respons ible for the project. Organ isationa l f inancial problems force reduc tions in the project budge t. Tools The cod e gen erated by CASE tools is ineffi cient. CASE tools canno t be integrated. Requirements Changes to requirements that require major design rewo rk are proposed. Customers fail to unde rstand the im pact of requirements change s. Estim ation The tim e requir ed to deve lop the software is unde restim ated. The rate of defect repair is und erestim ated. The size o f t he software is unde restim ated. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 29  Risk analysis  Assess probability and seriousness of each risk.  Probability may be very low, low, moderate, high or very high.  Risk effects might be catastrophic, serious, tolerable or insignificant. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 30  Risk analysis (i) Risk Probability Effects Organ isationa l f inancial problems force reduc tions in Low Catastrophic the project budge t. It is im possible to recruit staff wit h the skill s required High Catastrophic for the p roject. Key staff are ill at crit ical tim es in the project. Moderate Serious Software componen ts that shou ld be reus ed contain Moderate Serious defects which li mit their func tion ality. Changes to requirements that require major design Moderate Serious rework are proposed. The o rgan isation is restructured so that diff erent High Serious manage me nt are respons ible for the project. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 31  Risk analysis (ii) Risk Probability Effects The da tabase used in the system canno t process as Moderate Serious many transactions per second as expec ted. The tim e requir ed to deve lop the software is High Serious unde restim ated. CASE tools canno t be integrated. High Tolerable Customers fail to unde rstand the impact of Moderate Tolerable requirements change s. Requi red training for staff is not availa ble. Moderate Tolerable The rate of defect repair is und erestim ated. Moderate Tolerable The size o f t he software is unde restim ated. High Tolerable The cod e gen erated by CASE tools is i neffi cient. Moderate Insignif icant ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 32  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; ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 33  Risk management strategies (i) Risk Strategy Organ isationa l Prepare a briefing document for senior manage ment financ ial problems sho wing how th e project is making a very important contribution to the goa ls of the bus iness. Recruitm ent Alert customer of potential difficulti es and the problems possibil ity of delays, inves tigate buying- in componen ts. Staff illness Reorgan is e team so that there is more ove rlap of work and people therefore und erstand e ach other’s jobs. Defective Replace pot entia lly defective componen ts wit h bough t- componen ts in compon ents of known reli abilit y. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 34  Risk management strategies (ii) Risk Strategy Requi rements Derive traceabili ty info rmation to assess requ ir ements chang es chang e im pact, maximi se information hid ing in the design. Organ isationa l Prepare a briefing document for senior manage ment restructuring sho wing how th e project is making a very im portant contribution to the goa ls of the bus iness. Database Inves tigate the po ssibilit y o f buy ing a high er- performanc e performanc e database. Unde restim ated Inves tigate buying in componen ts, inve stigate use of a deve lopment time progra m gene rator ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 35  Risk monitoring  Assess each identified risks regularly to decide whether or not it is becoming less or more probable.  Also assess whether the effects of the risk have changed.  Each key risk should be discussed at management progress meetings. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 36  Risk indicators Risk type Potential indi cators Techno logy Late delivery of hardware or support software, many reported techno logy problems People Poor staff morale, poor relationsh ips amongst team m ember, job avail abil ity Organ isationa l Organ isationa l gos sip, lack of action by senior ma nage ment Tools Reluctance by team m embers to use tools, comp laints about CASE tools , demands for high er-powered workstations Requi rements Many requir ements change reques ts, cus tomer comp la ints Estim ation Fail ure to meet agreed schedu le, failure to clear reported defects ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 37  Key points  Good project management is essential for project success.  The intangible nature of software causes problems for management.  Managers have diverse roles but their most significant activities are planning, estimating and scheduling.  Planning and estimating are iterative processes which continue throughout the course of a project. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 38  Key points  A project milestone is a predictable state where a formal report of progress is presented to management.  Project scheduling involves preparing various graphical representations showing project activities, their durations and staffing.  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. ©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 39