Work vs. Estimated Hours
What is the difference between total work for a task and the estimated hours to complete the task? Why would I want different values in these task fields?
In many cases, these values will be the same. While planning your project, you may need to estimate the number of hours for a task without knowing exactly which resources will be applied. Upon applying the resource, you may determine that the work involved differs from your original estimate. Work hours can differ for various reasons. These reasons could include:
- A new resource that is estimated to take more hours while using the task as an on-the-job training exercise.
- A highly skilled resource is assigned to the task to accelerate its completion.
Another reason that you may want to maintain estimated hours is to measure the work calculations against this estimate if you are setting up resources with an auto-calculate on the work. Estimated hours won't change, so you can manipulate resource planning and work numbers without losing your original reference to the number of hours for the plan.
A simple example of how estimated hours may be defined could be the work involved in a basic car repair. An automobile manufacture may run tests with factory certified mechanics to determine the average amount of time it takes to do a radiator replacement on a specific make, model and year automobile. This controlled testing environment includes the standard set of tools, garage space and other environmental conditions expected in all dealer service centers. The average time it takes to perform this task is then used consistently within the project template as the estimated hours for the task. Work hours assigned to the task may vary based on the skill of the mechanic actually performing the work (trainee or experienced), the tools the mechanic has to perform the work (power tools or hand tools) and other environmental conditions (temperature in the repair garage).
In the event that the differences between work and estimated hours are of no consequence to your project and tracking the numbers separately has no value, always use work instead of estimated hours. Work is used for resource utilization calculations, making it the most important value for project schedule planning.