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Project Time Management. Activity Definition, Resourcing and Scheduling. Key Tasks. Activity Definition developing the work breakdown structure Activity Sequencing identifying relationships between activities Activity Estimation
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Project Time Management Activity Definition, Resourcing and Scheduling
Key Tasks • Activity Definition • developing the work breakdown structure • Activity Sequencing • identifying relationships between activities • Activity Estimation • ‘guessing’ the amount of time and resource required for a particular activity • Schedule Development • putting the Sequence and Estimation data together into a ‘plan’, a project schedule • Schedule Control • controlling and managing the project schedule (this will be dealt with a separate lecture)
Activity Definition • Need to know the Scope, The Time Constraints and the available Budget • Ideally these should be considered in this order • Activity Definition • Sequence the activities • Estimate the duration (time = money) • This should result in a Work Breakdown structure (WBS) • A list of key tasks, with sub-tasks identified where possible or where required • Resource Estimates against lowest level tasks – these can be aggregated back up into an overall resource requirement • WBS should be reviewed regularly – break larger tasks down into more detailed tasks at key points • transfer between stages of waterfall methodology or the phases of an iterative development for example
Activity Sequencing • Identify the order in which tasks can or must be performed • Identify dependencies between tasks • Mandatory – you cannot test code until it is written • Discretionary – don’t start design until analysis is complete • External – delivery of new hardware • Identify tasks that can be performed in parallel (i.e. they are not inter-dependent) • Identify where tasks can overlap (Coding and testing usually overlap at a high level, with low-level mandatory dependencies between parts of the system) • May need client input at this stage to identify areas of priority – i.e. if several tasks can be performed in parallel, is any particular task more important to the client than the others? • This stage is essential if project management tools are to be used • Allows the development of Network Diagrams, Gantt Charts and Critical path Analysis
Task Dependencies (from task to task) • Finish-to-Start • The to task cannot start until the from task has been finished (most common type of dependency) • Start-to-Start • The to task can only be started if the from task has been started • Finish-to-Finish • The to task can only be finished if the from task has been completed • Start-to-Finish • The from task must start before the to task can be finished (not used very often) • Resource Dependencies • Two (independent?) tasks may not be able to use the same resource at the same time • These can catch you out!
Activity Estimation • Need to estimate Actual Time (effort – man days?) and Elapsed Time (duration - just days) • Resources are assigned to tasks – you need to know how much ‘work’ a resource can do in a specific period of time • Resources can rarely dedicate 100% of their time to one job, make sure your plans do not assume that they do • Does involve guesswork, err on the side of caution • Allocate resource estimates at the lowest level of the Work Breakdown Structure • May involve ‘external’ resources (delivery of equipment or scheduling a meeting for example)
Activity Scheduling • Uses all of the data and information collected thus far to provide estimated start and end dates for a project • Aim is to produce a realistic and achievable schedule as a basis for monitoring progress as the project progresses • Common scheduling tools and techniques • Gantt Charts • Critical Path Analysis (Network Diagram) • PERT Analysis (often confused with network Diagrams)
Critical Path Analysis (Network Diagram) • Similar to Gantt chart but shows each task as a Box • Often confused with a P E R T Chart • Enter details of earliest start date and task duration (giving the earliest end date) • taking into account any dependencies along the way • This will enable an end date to be derived • You can then work back and enter the latest end-date and latest start date for a task • The difference between the latest start date and earliest start date is known as the Float • The critical path is the sequence of tasks that have no float time shown • The only way to introduce float is to either start the whole project earlier, or finish it later
PERT Analysis • Program Evaluation and Review Technique • A network analysis method which is used when there is a high degree of uncertainty about activity duration estimates • Applies the critical path technique to a weighted average duration estimation • These durations are then used in a network diagram as per the previous example • Uses probabilistic time estimates (in days), based on: • Optimistic estimate • Most likely duration • Pessimistic estimate • The Pert Weighted Average (PWA) duration is calculated as follows PWA = optimistic time+4 * most likely time + pessimistic time ------------------------------------------------------- 6
Scheduling Tips • Review the plan / schedule regularly • As the project progresses, vague details should become more firm – the WBS should become finer-grained • Plan with contingency in mind, do not schedule resources to 100% of their availability • If in doubt, over-estimate the duration of an activity • Track your actual progress against the schedule • Make sure you identify the critical path, and also which tasks can be done ‘whenever’ • If you come to a stop with one task, use the schedule to identify an appropriate alternative task to start instead
Practical work for this week • Download, or Print off the MS Project example worksheet from WebCT • Have a go at producing a Gantt chart – see if you can spot any resource issues and fix them • everyone’s will be different as you will probably choose different dependencies • Use Visio and have a go at producing a Network Diagram • Decide if you are going to produce a schedule for your Project and if so, in what format
Summary • Planning and Scheduling enables a picture of a project to be produced • This can be used to manage workloads, track progress and communicate responsibilities and progress • In order to produce an effective schedule you must • Define the activities to be undertaken (WBS) • Sequence the activities, identifying any dependencies • Estimate the resources required (don’t forget that most resources can only be used for a single task at any one time) • ‘guessing’ the amount of time and resource required for a particular activity • Develop a Schedule (Gantt or Network Diagram) • This process is very useful for project management purposes • However, care must be taken not to spend too much time fiddling with the finer details of the plan