Project Management Diploma: Activity Duration Estimating

Learn about the Activity Duration Estimating in the Project Management Diploma qualification.

The answer to the question ―How long will it take? depends on the accuracy of the estimates, the consistency of the work, and other variables within the project. The best a project manager can do is create honest estimates based on the information he’s been provided. Until the schedule is finalised, no one will know the duration of the project.

The tasks are first identified, the sequencing of the activities takes place, resources are defined and then durations are estimated. These activities are required to complete the project schedule and the estimated project duration. These four activities are iterated as more information comes available. If the proposed schedule is acceptable, the project can move forward. If the proposed schedule takes too long, the scheduler can use a few strategies to compress the project. We’ll discuss the art of scheduling in a few moments. Activity duration estimates, like the activity list and the WBS, don’t come from the project manager—they come from the people completing the work. They may also undergo progressive elaboration.

The process of estimating schedule activity durations uses information on schedule activity scope of work, required resource types, estimated resource quantities, and resource calendars with resource availabilities. The inputs for the estimates of schedule activity duration originate from the person or group on the project team who is most familiar with the nature of the work content in the specific schedule activity. The duration estimate is progressively elaborated, and the process considers the quality and availability of the input data.

For example, as the project engineering and design work evolves, more detailed and precise data is available, and the accuracy of the duration estimates improves. Thus, the duration estimate can be assumed to be progressively more accurate and of better quality. The Activity Duration Estimating process requires that the amount of work effort required to complete the schedule activity is estimated, the assumed amount of resources to be applied to complete the schedule activity is estimated, and the number of work periods needed to complete the schedule activity is determined.

All data and assumptions that support duration estimating are documented for each activity duration estimate. Estimating the number of work periods required to complete a schedule activity can require consideration of elapsed time as a requirement related to a specific type of work. Most project management software for scheduling will handle this situation by using a project calendar and alternative work-period resource calendars that are usually identified by the resources that require specific work periods. The schedule activities will be worked according to the project calendar, and the schedule activities to which the resources are assigned will also be worked according to the appropriate resource calendars. Overall project duration is calculated as an output of the Schedule Development process.

LMIT’s Diploma in Project Management is Now Endorsed by AIPM – Get Your Diploma of PM and You’ll Also Receive a Certificate from AIPM.

LMIT provides online training courses for the Cert IV Project Management BSB41507, the Certificate IV of Project Management and the Diploma of Project Management BSB51407 in Brisbane, Sydney, Melbourne, Perth, Adelaide and Canberra.


Published by: LMIT

Leave a Reply