[Project Management] Brooks' Law

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Although Moore's law is well-known (the performance of semiconductors doubled in 18 months), we know little about the Brooks' Law.

Http://commons.wikimedia.org/wiki/File%3AFred_Brooks.jpg * 1

Brooks was the developer of the operating system OS/1960s of the IBM System/360 in the 360 s. Later, based on his experience, he wrote a book about god of life.

This is an epoch book describing the difficulty of large-scale software development. IT practitioners must read a book. If you are a software developer or project manager, it is better to read this book. I also introduced it several times in my diary.

Let's not talk about the second chapter of the mythical man-month. Let's look at the example below. It takes 12 months for such a project, SO 3 people can complete the task in 4 months. Then, set the observation point A/B/C/D each month.

However, it takes two months to complete the result of a that needs to end in one month. This is two months later than the estimated time. What should I do? Managers have the following countermeasures.

1. Although the original estimation was correct, only the original project was wrong. That is to say, we can infer that there are only nine months left. Because of the nine-person-months of work, 9/2 = 4.5 people are required if two months are completed. Add two people to the three teams.
2. The original estimation was wrong. Instead of 12 months, it would take 24 months. It takes six months for the remaining 18 months. If two months are completed, 18/2 = 9 people are required. Add 6 people to the original three-person team.
3. Reschedule the task. Enough time to add to the new plan.
4. Adjust the work objectives. Reduce the workload.

So what method should we use. In the first two ways, without modifying the work objectives and work schedules, the expectations for achieving the Goals in the first four months will be shattered.

If two more persons are added, the training costs of the two persons, and the work completed by the three persons is done by five persons, the work needs to be rescheduled, and these costs are not included in the estimation, if the result is returned, the deadline cannot be completed. In the case of an additional 6 people, this cost is more.

This is the Brooks' Law. 「 Append personnel to delayed projects will affect the project progress 」

As Brooks wrote, if you cannot finish your work as scheduled, you can only reduce your work objectives.

This rule was found 50 years ago in software product development and is now correct. However, almost all developers do not understand the Brooks' Law, and even they do not know it.

Adding fuel to delayed projects is like adding fuel to the fire. Those who do not understand this rule should read The Mythical man-month well. Listen to me and read it carefully. As a consensus on project management before making decisions, everyone should read it carefully. We recommend that you adjust the job based on the particularity of each project.

Has your boss read The Mythical man-month? Try to ask.