A Summmary of the 12 Powerful Estimating Strategies
by Adele Sommers
Do you excel at predicting the time, funding, and resources your projects will require? If not, you're in good company! Nearly everyone I poll admits having the same challenge.
You may have noticed this phenomenon already: It's extremely difficult to calculate with any certainty how long a particular effort is going to take. This article explores some possible reasons why and offers 12 ideas for increasing estimating accuracy.
What Makes Project Estimating So Difficult?
When you ask any three people how long they think a particular effort could take, you might be surprised at the range of answers you'll hear. The possible reasons for the differences could include unfamiliarity with the work involved to an attempt to factor in unspoken requirements that seemed important to include.
Below are six of my favorite reasons for project estimating variability. I believe these are fairly universal, but are just a few of many possibilities:
1. Projects usually differ in at least some essential ways, making a "cookie-cutter" approach infeasible.
2. People chronically underestimate (but sometimes overestimate) time and effort.
3. Project requirements are typically very fuzzy at the start.
4. Requirements invariably shift over time.
5. Nearly everything about projects is dynamic.
6. Yet, projects are often constrained by finite conditions.
A confounding conundrum from the list above is that projects often involve many dynamic aspects, yet they almost always have finite budgets, schedules, or both. These contradictory forces make it extremely difficult to determine with pinpoint accuracy the hours and funding required, and thus set the stage for plenty of budget and schedule "collisions" during the life of the project.
When my own clients or colleagues ask me, "How long do you think this effort might take?" I, too, experience a knee-jerk reaction. Instinctively, a part of my brain that once excelled at solving math problems on timed quizzes goes into overdrive. "I know the answer!" it screams.
 Yet, unless that project or task is something I've performed many times before -- under very similar conditions each time, and with good records of my actual hours spent -- providing an accurate estimate can be quite elusive.
As I'm striving to imagine all of the stages and steps of a process, as well as fathom the unknown variables or things that could go awry, it's no wonder that I hardly ever guess 100% correctly, particularly for new endeavors!
Among the related challenges are detecting the presence of hidden or unknown variables that are difficult or impossible to anticipate, and sometimes even more difficult to resolve. Furthermore, we seem to have a strong human desire to please other people by telling them what they want to hear -- especially in the areas of budget and schedule. (After all, who wants to be the bearer of bad news?)
Robust Estimating Techniques Can Help Manage Project Risks
Did you know that estimating can be an invaluable tool for anticipating and managing these project uncertainties? Whenever we can determine our schedule and budget requirements with reasonable accuracy, it reduces the risk of running out of time, resources, and funding during a project.
Try using the 12 ideas below for boosting the accuracy of your estimates!
| 1. |
Maintain an ongoing "actual hours" database of recorded time spent on each aspect of your projects. Use the data to help estimate future projects and identify the historically accurate "buffer time" adjustments needed to realistically perform the work. |
| 2. |
Create and use planning documents, such as specifications and project plans. In the estimating stage, these are indispensable in helping to define the project scope. |
| 3. |
Perform a detailed task analysis of the work to be performed. If you are not intimately familiar with the tasks you need to estimate, you should plan to interview the people who are. (This is a "bottom-up" estimating method.) |
| 4. |
Use a "complexity factor" as a multiplier to gauge whether a pending project is more or less complex than a previous one. For example, Project B might be 200% more complex than prior Project A because there will be twice as many deliverables. (This is a "top-down" estimating method.) |
| 5. |
Use multiple methods to arrive at an estimate, such as a detailed task analysis, a complexity factor from comparing the effort with a prior project, and an adjustment buffer derived from your "actual hours" database. Look for the midpoint or average among them. |
| 6. |
Document caveats, constraints, and assumptions in your estimates to bound the conditions under which your estimates would be meaningful. Any work requested outside of the constraints would be considered out of scope. |
| 7. |
Propose adjusting the cost, schedule, quality or features upward or downward if the proposed budget or schedule seems inadequate to do the work involved. Usually clients can realistically expect only two or three out of four of these factors on a typical project. |
| 8. |
Consider more efficient ways to organize and perform the work if the project will have many constraints. One way is to dedicate specialists to performing certain tasks in an assembly line fashion, such as formatting documents, populating templates, editing, or testing. |
| 9. |
Plan and estimate the project rollout from the very beginning so that the delivery won’t become a chaotic scramble at the end. For example, during the estimating phase, you can propose using a pilot program or a phased implementation during the rollout. |
| 10. |
Consider a phase-based project approach, especially in very nebulous situations. The first phase focuses on requirements gathering and estimating subsequent phases. |
| 11. |
Prioritize the deliverables with your clients or stakeholders, right from the start, into "must-have" and "nice-to-have" categories. Then, in case of a schedule crunch, concentrate on first delivering the "must-have" items in the previously agreed order. |
| 12. |
Refer to your lessons-learned database for "20:20 foresight" on new projects. Consistently include best work practices in estimates so they’re always accounted for. |
In conclusion, by using a set of proactive 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!
Copyright 2011 Adele Sommers
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This week I gave another talk on estimating at an event jointly sponsored by my local chapters of 
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