Task estimates must be accurate to achieve project success. Most of all they effect the budget and schedule of a project. Currently worldwide, 7 out of 10 projects fail. And they fail because they are over budget, or finish late. This is tragic, not to mention expensive.
The good news is project managers can overcome these problems. The solution is to create excellent task estimates. This article focuses on Execution Task Estimates, including how to use them effectively.
Task Estimate Types
There are 2 types of estimates, Planning Task Estimates and Execution Task Estimates. So, let's begin by taking a look at both types.
Planning Task Estimates
During the initiation and planning phases of a project, managers use planning task estimates. Before committing to a project, senior management wants to know if the cost is justified. In addition, they want to know if the project will be complete when needed. To determine this, project managers create summary level planning task estimates.
Following project approval, project managers break down summary tasks estimates into detailed planning tasks estimates and organize them into a schedule. The schedule must meet the approved cost and finish date.
Execution Task Estimates
As work starts, tasks enter the execution phase of a project. Initially tasks retain their original planning task estimates. At this point, when revised, the estimate becomes an execution estimate.
Execution estimates are more accurate and reliable than planning estimates. When the resource updates them daily, they include current conditions. Furthermore, they come from the best source, the resource performing the working.
Making Execution Task Estimates
The best estimate comes from the resource working the task. In cases where they have done the task before, the estimate will be reliable. If the resource is new to a task, the estimate tends to be high. Because the estimate is high, it serves as built in risk mitigation. This is good. As the resource revises the estimate, it becomes more accurate and reliable.
It is best to assign tasks to a single resource and have them estimate it. Sometimes this is not practical nor possible to do. So, in this case, a single lead resource on the team working the task, should estimate the task.
Approving the estimate
In cases where the resource has not made the estimate, they should approve it before starting the work. When the resource approves the estimate, they have bought in and are planning for success. When forced to accept someone else’s estimate they are justified when they fail—after all, it is someone else’s estimate.
Revising the estimate
Revise all active tasks estimates each working day. Tasks with daily status reporting are more likely to complete on schedule. To do this, the resource simply reports the hours remaining to complete the task. Document the report and make it easy to submit. This step is so important it should be a condition of employment in the case of an employee, or condition of engagement in the case of a contractor.
Conclusion
I find that most project managers create planning estimates properly. Yet, I also find that they create execution estimates improperly, or not at all.
Managers who properly implement execution task estimates will benefit. Most of all, the resource working a task needs to estimate that task. And, the resource needs to do that every working day.
