To remedy these shortcomings, below are 12 point for boosting the accuracy of your estimates:
- Maintain an ongoing “actual hours” database of the recorded time spent on each aspect of your projects. Use the data to help estimate future projects and identify the historically accurate buffer time needed to realistically perform the work.
- Create and use planning documents, such as specifications and project plans.
- Perform a detailed task analysis of the work to be performed.
- Use a “complexity factor” as a multiplier to determine whether a pending project is more or less complex than a previous one.
- Use more than one method to arrive at an estimate, and look for a midpoint among all of them.
- Identify a set of caveats, constraints, and assumptions to accompany your calculations, which would bound the conditions under which your estimates would be meaningful. (Anything that occurs outside of those constraints would be considered out of scope.)
- If the proposed budget or schedule seems inadequate to do the work, propose adjusting upward or downward one or more of the four project scoping criteria: cost, schedule, quality, and features
- Consider simpler or more efficient ways to organise and perform the work
- Plan and estimate the project rollout from the very beginning so that the rollout won’t become a chaotic scramble at the end. For instance, you could propose using a minimally disruptive approach, such as a pilot programme or a phased implementation
- In really nebulous situations, consider a phase-based approach, where the first phase focuses primarily on requirements gathering and estimating
- Develop contingency plans by prioritising the deliverables right from the start into “must-have” and “nice-to-have” categories
- Refer to your lessons-learned database for “20:20 foresight” on new projects, and incorporate your best practices into future estimates
In conclusion, by using a set of proactive estimating techniques to scope, plan, and constrain your project conditions, you can dramatically improve your estimating practices, reduce and mitigate risks, and greatly increase your project success rate!