There are four aspects to Project Time:
Once having defined the activities or tasks you must decide how long each task will take before they can be arranged in sequence.
Duration and Effort
There are two kinds of time commitment for each of the activities of a project.
- Duration is the amount of time from the beginning of the activity to its completion. Duration has a direct effect on the schedule.
- Effort or resource time is the amount of time required for the people to complete it. Effort is directly related to the cost of the time expended on the project.
Duration and effort are not usually the same. For instance an approval may take three weeks from start to finish, giving it a duration of three weeks, but it might only take one or two hours of your own time, leaving you free to do other things. On the other hand a task might involve three people for three weeks. In which case the duration is three weeks but the effort is equal to nine weeks.
All estimates are just that - informed guesses about how long a particular task will take to complete. In the project risk template note down any risks associated with the estimates of duration you have made.
When estimating the duration of an activity or task consider:
- Part-time working on a project
- Time lost and interference from non-project activities
- Skill and experience of the people who will be doing the task
- Priority of the project - will other activities take precedence if time is short?
- Availability of staff with special skills
Be realistic with your estimates - don't massage estimates to suit unrealistic deadlines. A project that is manipulated to meet an unrealistic timeframe will invariably fail!
The linked Activity Durations template might be of assistance.
Using the activities and the durations we can now place them in sequence and develop the Schedule for the project.
The schedule allows progress of the project to be assessed, communicated and coordinated and it identifies key milestone dates to be met.
Some tasks can be done at the same time. Others will be dependent upon previous tasks being finished.
The "sticky" note method:
Particularly early in the project agreement, "buy-in" and the advantages to be gained from expert opinion is best obtained through involvement of the key stakeholders in developing the initial schedule. Simply ask the participants to arrange the sticky notes from the Work Breakdown Structure in order of sequence. Then draw arrows between the sticky notes to indicate the order of events and the dependencies.
The diagram above for the first phase of a staff survey project is called a Precedence Network because it describes the dependencies between activities or tasks.
The pathway through the sequence in which the total of the durations is greatest is called the CRITICAL PATH. It indicates the minimum total time from start to finish of the project or phase.
In the example above, the CRITICAL PATH runs through the following activities - 'identify questions' - 'obtain approval' - 'conduct initial interviews' - 'refine survey' because this pathway is the longest total duration.
The total length of the critical path is 27 working days. That is, the project will take a minimum of 27 working days from start to finish. The activities - 'literature search' and 'define focus groups' are not on the critical path. They can be done in parallel with other activities.
There are always risks associated with a network or schedule. The most influential risks in terms of the schedule tend to be those on the critical path. For example a risk could be associated with the activity 'obtain approval', especially if the approval requires sign-off by senior managers. If the duration has not been estimated correctly the initial interviews would have to be delayed. Often it is difficult to get focus groups together. This could constitute a major delay to the entire project.
You should enter any risks associated with the schedule in the Project Risk template.
Reducing time to completion - shortening the critical path:
If your network calculations do not meet the scheduled completion date for the project, as per the project objectives, the critical path might need to be shortened. This can be done by adding resources, which will allow activities to be completed in a shorter duration, or certain activities might be undertaken at the same time, or in parallel. It is not good practice, and is particularly unfair to project personnel, to "massage" activities into unrealistic timeframes!
This tool is used to indicate key dates. Milestones are either set for the projects or established by the project team as dates to be met. Milestones might indicate the key dates to be met during the execution of the project, such as a report to a board meeting.
Generally milestone plans are effective communication tools. They can be used to create a sense of urgency and to reinforce with key stakeholders and the project team the key dates in the program to be achieved.
Milestone plans are not used as planning tools unless the project manager is extremely familiar with the type of project or the project is a "fuzzy" project which must be planned step by step.
An example of a Milestone Plan for a training session is shown below:
The milestones are commonly included in the Project Proposal document.
This tool is one of the most easily understood of the schedule formats. It lists the tasks with a task bar next to each task showing its time duration.
The project schedule is commonly presented as a Gantt chart. It is an excellent communication tool, however, as the Gantt chart does not show dependencies very clearly it is less easily manipulated than the precedence network.
Milestones (traditionally represented by a diamond shape) can be plotted on the bar or Gantt chart for easy reference to key dates in the schedule.
Beware too much technology too soon in the process!
In recent years the use of computer enhanced scheduling systems has meant that the production of the schedule has become a solitary activity.
It is strongly advised that the initial schedule be created as a "group activity" otherwise there are risks of insufficient commitment by key stakeholders to the durations and dependencies and lack of expert information at a key stage in the planning process. Once the key stakeholders and project team have ownership, the schedule can be converted using an appropriate computer based scheduling program.
It is unlikely that one person (the scheduler) will have expert knowledge of every task in the project!
The linked Gantt chart template might be of assistance.