Adding Manpower to a Late Project Makes It Later – Effectiviology

• “Nine women can’t make a baby in one month”

• “You get water by digging one well a hundred feet deep, not a hundred wells one foot deep”

• “What one programmer can do in one month, two programmers can do in two months”.

Brooks' law can be expanded in three ways to generalize it and consider it in other contexts.

• Brooks's law can be applied to other endeavours such as different types of business, academic, and hobby projects.
• Brook's law can be applied to negative outcomes other than delays. E.g., adding people to a software project might lead to a worse product or increased conflicts between team members.
• Brook's law can be applied to resources other than manpower. For example, adding money to a certain project might not lead to it finishing faster because spending more money doesn't address the real problem.

• Adding more people to a project doesn't mean it will be completed faster.
• People who are already working on the project must spend time training newcomers.
• It takes time for new people to join the project to become productive.
• Time is spent on communication rather than work, which can quickly rise as people are added to a project. The larger a group is, the more agreement and organization it will need.
• Certain tasks cannot be divided into partitions that separate people can handle.

Whether or not Brooks' law applies in a situation depends on various factors, such as:

• The attributes of the people working on the project - their ability and willingness to teach others.
• The attributes of the people who are being added to the project - their ability and willingness to learn new material.
• The number of new people added to the project.
• The overall team size.
• The group's social dynamic.
• How group members are expected to communicate.
• The hierarchy and decision-making process.
• The type of tasks involved in the project
• Why additional manpower is added.

• To account for Brooks's law, you should avoid assuming that adding more resources to a project will help.
• Assess whether you should add resources, how many and in what way.
• Consider how adding more resources can help the project or harm the project.
• Consider how effective adding the resources will be in leading to the desired outcomes.
• Consider how efficient adding resources will be in terms of avoiding wasted resources.
• In some instances, changing the project's scope or moving its deadline is preferable.

If someone else in your organization insists on adding more resources, consider doing the following:

• Ask them to explain their reasoning, and explain the flaws in it.
• Explain to them why it’s a bad idea, potentially while mentioning Brooks’ law.
• Help them find an alternative solution.
• Convince them to add fewer resources.

A humorous solution is the Bermuda plan, which involves putting 90% of a company’s programmers on a boat and sending them to Bermuda so that the remaining 10% can finish the work.