Project Management Plan - How to Estimate Activity Resources

March 13, 2013 | Author: PM Hut | Filed under: Project Plan Development, Scheduling

Project Management Plan - How to Estimate Activity Resources
By Sheena Davison, Northwest University

There are two things that are very important to determine when calculating the amount of resources each activity is going to take. First, you must determine what level of competency you need. At this point it’s important to not look at what experience or skill set you have available to you, but truly look at what is needed to get the job done. Secondly, you need to determine how much time the activity will take if the needed competency level is met. As an example, it make take a level 2 Engineer 20 hours to write the code that you need for the software, that 20 hours is the amount of time needed for the activity of writing code. Often, the easiest way to determine the amount of time needed is to ask someone at the level of competency needed, the amount of time it would take them to complete the activity. There is no substitute for expert judgment and it’s very important to bring in the subject matter experts as early as possible.

There are other ways of analyzing the activity resources and each could affect your project in a different way. Before starting your analyzing it’s important to determine where your project is most forgiving. Is the timeline set in stone or is it more flexible? Is the cost of the project tightly budgeted or is there some forgiveness there? Once these questions have been answered you can determine which method you would prefer to use.

Published estimating data is one valuable resource that has a tendency to cost more money. This is using the assumption that the activity that you are having done, has been done before. Using published data would provide you with reports that would give you estimates of how much time these tasks have taken in the same or similar projects.

The second alternative resource is more time intensive, but is very accurate. Bottom-Up Estimating is exactly what it sounds like, it’s calculating the time it takes to complete a task from the very bottom task, all the way to the top. As an example, you have work package 1.3 and that work package has 8 tasks below it that need to be completed in order for the work package to be considered “complete”. You would then take task number 1.3.8 and determine how much time that task would take, then move on to 1.3.7 and determine how much time that task would take, then 1.3.6, 1.3.5, 1.3.4 and so on. Once each task has been estimated, you would then be able to add together all of the times and determine how long the work package would take. You would follow this process for all of the work packages to determine the overall resource time for the project. It’s incredibly important to have the subject matter experts involved in this estimating, even writing the bottom-up analysis for you, when possible. Just don’t be fooled, there are pitfalls that you need to avoid:

  • If you’re having troubles coming up with the estimated numbers, chances are your tasks are too vague. If this is the case, take some time to revisit the tasks and defining them more thoroughly and try estimating again.

  • Understand that your estimate may not match the budget and that’s okay. It’s important for the estimate to be accurate because it sets expectations. If it is found that the project needs to be changed because of the estimates, that’s okay too – but that doesn’t need to be a worry at this point. Good, honest and accurate numbers are most important.

  • It’s easy to want to “pad” the estimated times “just in case something happens”. Don’t do it. It’s unethical to lie about the time it may take to complete a task. It is understood that these task times are estimates or your best, most educated guesses you could provide.

Remember, you always have less knowledge at the beginning of your project. If you find that some of your estimates are off, you will be able to correct those estimates as you gain more knowledge.

Northwest University opened to students on October 1, 1934. It is a regionally accredited institution awarding associate, baccalaureate, and master’s degrees.

Note: Implicit permission was given to republish this post, as the article was not copyrighted.

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