Software Engineering Institute

This column is the last in a series about estimating. If you have read the prior 10 columns, you now know how object-oriented methods can help you make good estimates and plans. This column describes some data on how the PROBE method that is described in these articles has helped engineers make better estimates and do better work.

If you are new to this series of columns on Estimating with Objects, the first was in the July 1996 Object Currents issue. The prior columns in this series gave an overview of estimating and defined the steps needed to make size and resource estimates. If you have not read these earlier columns, you should look at them to understand the context for this discussion and to see how these various estimating topics relate. To repeat what I have said in previous columns, the estimating method described here is called PROBE. If you want to learn the PROBE method, you should read my book A Discipline for Software Engineering, from Addison Wesley. This book introduces the Personal Software Process (PSP)^SM, which is an orderly and defined way for software engineers to do their work.

This month's column concludes the discussion of how object-oriented techniques can help you estimate and plan your work. To make a project plan, you need a resource estimate and, to estimate resources, you need to estimate the size of the product you plan to build. Also, to make good estimates, you need historical data on the sizes and development times for the programs you have previously written. The previous columns described how to gather these data and how to use them to make size and resource estimates, judge the accuracy of these estimates, produce a project schedule, and track the work against the plan. This column concludes with data on how these methods work in practice.