When estimating the effort for a project, consider the following
- The ‘Real’ Duration of Tasks. Ensure that the estimates include the effort and time required for gathering and interpreting information, as well as other activities pertaining to project management and business analysis.
- Decisions, Reviews and Approvals. Adequate time must be allocated to the tasks for resolving project issues, performing quality assurance, reviewing and accepting products and results, making key decisions, and getting approvals.
- Full scope of work. Is the full scope of the project work included within the estimates? Does this include quality assurance, re-work, publishing, and archiving of deliverables?
- Splitting Tasks. Tasks that are spread out over a great deal of time, or start and stop through the schedule will require effort in order to pick up where the activity was last left off.
- Full-time vs. part-time? Ensure estimates account for the percent of time resources are available to the project.
- Parallel activities. If resources are expected to work on more than one activity at once, their duration will be impacted.
- Defining the Working Day. When people define the working day, they typically refer to the standard 7-hour UW work day. However, the standard working day may be far less considering productivity interruptions such as
- Disruptions such as telephone calls
- Lost time from holidays, vacation, and sick time
- Non-project time such as meetings, expense claims, supervision, and other administration activities.
- Always include contingency. A contingency is something that’s expected to be spent. Project Managers should determine how contingencies will be handled within their projects and add appropriate contingencies.
- Avoid making numbers fit the budget. Make the estimates realistic to avoid having to justify an overage due to optimistic estimates.
- Communicate team assumptions. A common mistake when estimating is listing tasks and numbers while not specifying assumptions behind the numbers. Employ good requirements management by making sure team members provide clear details on what they’re estimating to avoid costly surprises later in the project.
- Avoid using only high-level breakdowns. The more detailed the breakdown, the more accurate the estimate and the easier it is to get the whole team on the same page.
- Double-check for commonly overlooked activities. It can be easy to overlook tasks such as meetings, feedback, and bug fixing. These often-overlooked tasks can frequently derail estimating efforts. Some of these may be easier to estimate based on percentage of work by looking at previous projects.
- Include the accuracy of the estimate. Estimates are guesses based on assumptions, but some guesses are more accurate than others.