3-Project Planning and Implementation
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Transcript of 3-Project Planning and Implementation
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 1
Project planning
Probably the most time-consuming project management activity.
Continuous activity . Plans must be regularly revised as new
information becomes available. Different types of plan may be developed to
support the main project plan that is concerned with schedule and budget.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 2
Informal vs. Formal planning
Informal planning – projects involving few activities ,resources, constraints and inter-relationships can be visualized and planned informally.
Formal planning – when a project crosses a certain threshold level of size and complexity, informal planning has to be substituted by formal planning.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 3
Functions of planning
Provide a basis for organizing the work on the project
Allocate responsibilities to individuals Provide a means of communication and co-
ordination of all those involved in the project. Induce people to look ahead. Develop a sense of urgency and time
consciousness Establish the basis for monitoring and control.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 4
Areas of Planning
A comprehensive project planning covers the following:
Planning the project work- The activities must be identified. They should be properly scheduled and sequenced.
Planning the manpower and organization- estimate the manpower requirements-managers, technologists, operators, and others
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 5
(------- contd)
Planning the money- The expenditure must be budgeted in a time-phased manner
Planning the information system – The information required for monitoring the project must be defined
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 6
Stages in the Life cycle of a project
Project development and preliminary engineering
Bidding and contract negotiation Engineering design Purchase and procurement Construction Commissioning
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 7
Concepts in planning these stages
1. Rolling wave concept – when detailed planning is done for one stage, summary planning would be done for the remaining stages.
2. Integration concept - planning for all the stages must be integrated. It stems from the inter-relationship among various stages of the project.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 8
Tools of planning
Bar chart , also referred to as Gantt chart or the multiple activity chart.
Net work techniques
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 9
Bar chart
- is a pictorial device in which the activities are represented by horizontal bars on the time axis
- Advantages of bar chart: Simple to understand Can be used to show progress Can be used for manpower planning
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 10
Limitations of bar chart
Can not show inter-relationship among activities on large and complex projects
Physical limit to the size of the bar chart may limit its application
Can not easily incorporate frequent changes in the project
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 11
Network techniques
In these techniques the activities, the events and their inter-relationships are represented by a net work diagram, also called arrow diagram.
These are more sophisticated than the traditional bar chart.
Advantages:
(i) They can effectively handle inter-relationships among project activities
(ii) Timely identification of the activities which are critical
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 12
(contd…..)
(ii)Timely identification of the activities which are critical to the completion of the project
(iii) They can handle very large and complex projects
(iv) They can be easily computerized and updated
Drawbacks:
(i) Being more complicated the project personnel may not be able to understand easily.
(ii) The do not define an operational schedule which tells who does what and when.
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 13
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 14
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 15
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 16
Milestones in the RE process
Evaluationreport
Prototypedevelopment
Userrequirements
Requirementsanalysis
Feasibilityreport
Feasibilitystudy
Architecturaldesign
Designstudy
Systemrequirements
Requirementsspecification
ACTIVITIES
MILESTONES
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 17
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 18
The project scheduling process
Estimate resourcesfor activities
Identify activitydependencies
Identifyactivities
Allocate peopleto activities
Softwarerequirements
Activity chartsand bar charts
Create projectcharts
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 19
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 20
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 21
Example : Task durations and dependencies
Activity Duration (days) 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 22
Example: Activity network
start
T2
M3T6
Finish
T10
M7T5
T7
M2T4
M5
T8
4/7/03
8 days
14/7/03 15 days
4/8/03
15 days
25/8/03
7 days
5/9/03
10 days
19/9/03
15 days
11/8/03
25 days
10 days
20 days
5 days25/7/03
15 days
25/7/03
18/7/03
10 days
T1
M1 T3T9
M6
T11
M8
T12
M4
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 23
Example : Activity timeline4/7 11/7 18/7 25/7 1/8 8/8 15/8 22/8 29/8 5/9 12/9 19/9
T4
T1T2
M1
T7T3
M5
T8
M3
M2
T6
T5
M4
T9
M7
T10
M6
T11M8
T12
Start
Finish
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 24
Example: Staff allocation
4/7 11/7 18/7 25/7 1/8 8/8 15/8 22/8 29/8 5/9 12/9 19/9
T4
T8 T11
T12
T1
T3
T9
T2
T6 T10
T7
T5
Fred
Jane
Anne
Mary
Jim
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 25
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 26
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 27
The risk management process
Risk avoidanceand contingency
plans
Risk planning
Prioritised risklist
Risk analysis
List of potentialrisks
Riskidentification
Riskassessment
Riskmonitoring
©Ian Sommerville 2004 Software Engineering, 7th edition. Chapter 5 Slide 28
Risk identification
Technology risks. People risks. Organisational risks. Requirements risks. Estimation risks.
©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 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 31
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 32
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 33
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.
Key points