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)

Gantt Charts – The Base data

How it looks as a Gantt

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

DurationEarly Finish

Late Start SlackLate

Finish

Early Start

Task Name

A simple example DurationEarly Finish

Late Start SlackLate

Finish

Early Start

Task Name

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