In our last posts, we discussed the two initial steps of effectively estimating:
- Define the scope of the project or tasks that you are estimating.
- Make a detailed list of tasks.
Now, that we have our detailed scope and work defined, we need to analyze each task and total our estimate. In my system, I break this out into six distinct steps, in practice this analysis is happening as a holistic step. I like the break out the steps, so that nothing is missed in the process. The detailed steps are:
- Identify both external dependencies and internal dependencies.
- Review each detailed task and mark the following:
- Degree of difficulty (high, medium, low)
- Amount of experience you have with completing a task of this nature (none, some, substantial)
- Potential unknowns – what could derail this particular task?
- Estimate each individual task.
- Add buffers for tasks with dependencies, minimal past experience and significant potential unknowns.
- Total your estimate.
- Map your estimate out on a calendar.
Identify both external dependencies and internal dependencies: Something that will readily derail a timeline are dependencies that are not properly planned for. This can be interdependencies, which are tasks you and/or your team own as part of the project that are dependent on other tasks that you and/or your team own and external dependencies that you do not control.
In the example of the kitchen remodel, many of the detailed tasks for painting the cabinets have potential interdependencies on other components of the remodel. For example, choosing the color for the cabinets may be dependent on choosing other elements of the kitchen design, like the countertops and backsplash. The installation of the countertops and backsplash would also need to be properly planned for. It would be a headache to have the granite installer show up 3 hours after that first coat of paint is applied to the cabinets.
Mapping out the dependences will also show when there are potential delays from external dependencies. One can assemble the perfect plan, but if they are dependent on the delivery of materials or availability of resources that they do not have direct control over, there are inevitably delays.
Review each individual task: Now, that we have analyzed our dependencies, which can be the biggest drivers of inaccurate estimates, we can move into further analysis of each task for potential drivers of overages. The degree of task difficulty, experience the resources have in completing the task and potential unknowns should be given a great deal of thought.
Once the dependencies and individual tasks are analyzed, the scope and assumptions should be updated to note any assumptions that have been made in the estimating. For example, in the kitchen remodel, there is a dependencies on the availability of paint and other materials. It can be noted that the estimated timeline assumes the availability of materials when needed rather than trying bake time into the estimate to compensate for delays due to material shortages.
Estimate each individual task: Now it is time to estimate each individual task. I suggest estimating in hours as this granularity of time will provide for better estimate to actuals during the execution of the project. Some task management software allows for tracking by the minute, this is excessive in most work environments.
Add buffers for tasks with dependencies, minimal past experience and significant potential unknowns: You completed your task estimates, now go back and think through your task analysis. Be sure to have a buffer (additional time in your estimate) or a well defined assumption for all dependencies, potential resource issues, difficult tasks, and significant unknowns.
Total your estimate: This is an easy step, simply add up all of the time allocated to each task in order to arrive at a summary estimate.
Map your estimate out on a calendar: This is a step that I often missed in my early days as a project manager. The calendar is a landmine filled with weeks where many companies essentially shutdown, required training, federal holidays, three day weekends that morph into four day weekends, religious observances, and individual vacations. The plan needs to fit on to the calendar work days. Assuming 160 hours per month, per resource will inevitably result in a project that does not complete on time. There are countless reasons why individuals do not have 160 working hours per month. It is key to put your plan onto a calendar that accounts for all of the landmines.
Now, it is time to begin your effort. This step in my plan is “Begin your effort, reviewing your estimate on an ongoing basis and tracking actuals to your estimate.” I find that few projects review their original estimates against the actual time each task takes during the project. I appreciate an ongoing analysis of what was right and wrong may not be fun, but this is key for two reasons:
1 – Comparing the actuals to the estimate helps provide an understanding of overages that can be communicated to stakeholders.
And, most importantly, the actuals to estimate comparison facilitates the most important step in becoming effective at estimating: Step 10 – Learn from your experience.
Happy estimating!
Estimating is just one of many key skills to be effective in the workplace. I encourage all to explore other skills that are key to career growth. A great resource for this exploration is Career Growth Development | My Blank Job, which brings together a wide variety of resources for career growth.