Software Estimation: Demystifying the Black Art (Developer Best Practices)

There's a number of books out there now on software estimation, certainly more than there were a few years ago. I've worked my way through a few of them as I found myself involved in software estimation for larger (50 person +) projects that required a little more than the seat of the pants guesstimating techniques that so many of us IT project managers use with the usual results. Doesn't matter so much on smaller projects, but on large multi-year projects inaccurate estimates can have a deterimentary effect on one's career. The book really does demystify estimating. It does a good job in Part 1 (5 chapters) of explaining crtical estimation concepts - very important for the neophyte at more formal estimating. Part 2 (12 chapters) covers a range of "Fundamental Estimation Techniques" and does it really well. There's enough information to get you started without being overwhelming Part 3 (Specific Estimation Challenges - 6 chapters) covers challenges you will face with your estimating and presents useful practical approaches to these. All in all, it's a very useful and practical reference book for all those involved in estimating and presented at a level that the beginner can absorb and use practically. It doesn't overwhelm with detail on any one technique, it's more an introduction to the field, but an introduction that will get you started successfully and form a basis from which you can specialize further. Steve McConnell's a well-know author with a number of useful books published previously - "Rapid Development" and "Code Complete" in particular. He's gpt experience in the field and he writes well, the books coherent, logically structured and it won't (unlike so many technical books) put you to sleep.

McConnell immediately differentiates between software estimation as a science and software estimation as an art within the first pages of the introduction to this work - he explains that while software estimation research is currently focused on improving estimation techniques so that project results are achieved within +/- 5% of esimated results, the techniques of which are best included in commerical software estimation tools that are used to pursue the science of estimation for very large projects, the typical software organization struggles to avoid estimates that are incorrect by 100% or more, and Software Estimation discusses the estimation techniques comprising, although not limited to, the art of estimation that will reduce estimation error to about 25% or less, which is what the vast majority of software projects need. This book is absolutely the best software estimation text I have read to date. As Joel Spolsky mentions on the back cover of the book, the vast majority of software project managers still think that estimates are based on multiples of a gut feel. This philosophy completely ignores the vast body of research and hands-on experience of the last few decades. McConnell explains with sufficient depth all of the ways to create "ball park" estimates, and if there is one chapter of this book that you read, Chapter 4 "Where Does Estimation Error Come From?" is the one that I recommend - the explanation of the Cone of Uncertainty is so well explained that anyone can understand it. Although I have never read Code Complete by the same author, I did purchase Rapid Development several years ago - and I must say that McConnell (or at least his editors) has vastly improved his writing skills. This book is less than half the size of Rapid Development, and while I fell asleep while reading that book I was able to conduct a cursory reading of over half of Software Estimation in one evening and immediately apply some of its concepts on a work project the following day. A great modern follow-up to The Mythical Man-Month by Brooks and an excellent primer to reading SEI's Estimating Software-Intensive Systems by Stutzke on the science of estimation.

I must admit, I was very surprised to see an excellent source on software development time and cost estimation from Microsoft Press. However, when I saw that the author was Steve McConnell, the author of Code Complete (which I thought was a great book) I knew that this book would have something to offer. His definition of the purpose of software estimation is important: "The primary purpose of software estimation is not to predict a project's outcome; it is to determine whether a project's targets are realistic enough to allow the project to be controlled to meet them." From this premise, the author continues to prove that software estimation is about determining if you can control a project to bring it in reasonably close to the organization's targets. In addition to this, Mr. McConnell's arguments for overestimation being better than underestimation are rather good and have convinced me to continue using my risk time and budget items that I've been using and recommending to others. In chapter 4, the author identifies four main sources of project estimation errors: -Inaccurate information about the project being estimated -Inaccurate information about the capabilities of the organization that will perform the project -Too much chaos in the project to support accurate estimation (that is, trying to estimate a moving target) -Inaccuracies arising from the estimation process itself That last one presents the need for me to give a little more information. The author suggests that bias and subjectivity of the estimator cause major estimation errors in the estimation process. This is proven through exercise case studies of time estimation in training classes. The author found that the more "control knobs" (impacting factors considered when estimating the project) used in the estimation process the greater the probability of variance in the estimates. He attributes this to bias and estimator subjectivity and it makes a lot of sense. In the end, this book will make you a better estimator and project manager and I highly recommend it. Tom Carpenter, Author: Wireless# Certification Official Study Guide, CWSP Certification Official Study Guide, Project Management for the IT Pro, and Foundations of Effectiveness

This is a great book for software project managers, or any professional directly involved with the difficult task of predicting how long will it take and how much will it cost to develop a software project based on its initial requirements/scope definition. Steve McConnell is an essential author in regards to software development issues, and this book delivers on its subtitle: "Demystifying the Black Art", showing the main aspects involved in software estimation and how it is possible to produce reasonably accurate estimates using techniques based on things like group work, personal experience, expert judgement, past history and a lot of common sense. Chapter Four ("Where Does Estimation Error Come From"), with its description of the "Cone of Uncertainty", is a must-read for those who want to understand how good an estimate can be, and where we make the most common errors so we can avoid them. The book doesn't delve deep into any specific technique, what makes it more useful and easier to read, since some techniques are so complex that it takes hundreds of pages to describe them well. I believe it will become another classic, like "Rapid Development" and "Code Complete"!