March 24, 2008 – Estimating Lessons Learned – Estimate Creation
No matter which estimating type you use, there are common steps to creating one.
Lesson 6 - Include your Team. Don’t estimate in a vacuum. Using the team sets you up for success on two fronts. First, the estimate will be more accurate. They know the details of what needs to be done, without which you are just pulling a number out of your hat. Second, it builds buy in and commitment. If they are involved in the process they have ownership of the final result.
Lesson 7 - Break it down. The question always asked is “How do you eat an elephant?” Frankly, I don’t believe anyone eats elephants any more. It is probably a cholesterol thing. How do you get in shape is a different animal. Reduce it to chunks: Diet, Exercise, and Support. Then break those into pieces. Diet - What to eat and what to avoid. Exercise – Classes, weights, aerobics, swimming or walking. Support – find a group and meet regularly. Broken down you can wrap your mind around it.
Traditionally projects create a Work Breakdown Structure (WBS) to identify the work products. Another approach is using Use Cases to drill to specific stories. However you do it, chop the big chunks into smaller units that can be more accurately estimated.
Lesson 8 – Mix and match estimate types. There is no rule that says you must estimate all pieces the same way. If there is a piece that looks like something you have done before, use the Analogous technique to estimate it. For reports the Parametric type may be appropriate.
Lesson 9 – Ask the right questions. One of my previous employers estimated a project to complete a previously implemented system across an enterprise. The question they failed to ask? “Does it work in the area it was first implemented?” The answer would have been “no” and the estimate would have been considerably higher.
Lesson 10 - Document your reasoning. How you came up with the number is as important as what the number is. We’ll delve into this more next week.
Lesson 11 – Sketch a calendar. Create a sanity check for your estimate. Lay out the high level estimate on a timeline by month. Estimate the number resources you need, when you will need them and for how long. Include the number and type of resources broken down by week. Keep it simple as illustrated in the graph below.
I purposely used Excel and kept the image rough so that it does not convey any semblance to accuracy. Does the resource effort look accurate compared to the numeric estimate? Sometimes this rudimentary method allows you to see it from a different angle and find gaps in your estimation.
Lesson 12 - Add Project Management. Include time for status reporting, timekeeping, status meetings and other items. Be aware of other tasks that Project Managers may be pulled into like steering committees, metrics management and resource management. For larger projects a Project Coordinator or even sub-project leads will be necessary to help manage the effort.
In some respects establishing the actual estimate is learned and perfected as you do more estimates. What are some of the tricks you have picked up over the years?
