# IT Employment

## General discussion

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### What is a man month?

By ·
In a software development cycle, What is a man-day and man-month? What is the caluclation behind it?

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### What is a man month?

by In reply to What is a man month?

One person working one day equals one man day.

Two people working together for one day equals two man days.

Three people working together for one day equals three man days.

Twenty people working together for one day equals twenty man days.
The calculation behind it is simply determining how much time (in days) will be required to complete a project. The project will take "X" amount of TOTAL hours (or days). Five people working on the same project for five days takes twenty five man days to complete.

The same applies for man-months.

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### What is a man month?

by In reply to What is a man month?

A man month is ALSO the time it's taking you to reply to these very generous and well thought out answers. No, wait a minute. You've taken MORE than a man month, more than two, more than three, more than.....

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### What is a man month?

by In reply to What is a man month?

The question was auto-closed by TechRepublic

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### What is a man month?

by In reply to What is a man month?

It is the amount of actual hours a 'man' (person) can work in a Month. Example: a man day consists of 8 man hours. A man week (5 man days) = 40 man hours, etc. This can vary to the hours per day the company has designated as a 'work day', ie. 37.5is typical for European companies.

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### What is a man month?

by In reply to What is a man month?

The question was auto-closed by TechRepublic

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### What is a man month?

by In reply to What is a man month?

A man month (I prefer "person month") is the amount of work that one person can do in one month.

It is NOT a duration. It may take several months to apply one man month of work to a job if you only have someone working part-time on that job. Likewise, you can apply one man month of work in a very short period of time if you have several people working on that job.

Man months can be different sizes, depending on the company you work for. Obviously, a company that has a nine-hour work day will be able to apply more effort than a company with only a seven-hour work day.

# man months = ttl hrs worked / normal hrs worked in one month

Notice that even the idea of "month" is not simple. Feb 2003 has 20 working days. Mar 2003 has 21 working days. Jan 2003 had 22. I know this is only a one or two day variation, but it could introduce an error of 5% to 10% in any calculation you do. You may wish to standardize the term month. I typically use 21 days:

365 days per year * (5/7) / 12 = 21.7 working days per month. Factor in statutory holidays, and you are left with about 21 working days per month.

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### What is a man month?

by In reply to What is a man month?

The question was auto-closed by TechRepublic

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### What is a man month?

by In reply to What is a man month?

When calculating a man-day or a man-month, you should also take into account the number of hours a day the employee will actually be working on the project. For example, if the employee is also providing support for an application for about 2 hours a day, then a man-day might be 6 hours. Remember to take into account other activities the employee will be engaging in: education, department meetings, other projects, etc.

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### What is a man month?

by In reply to What is a man month?

The question was auto-closed by TechRepublic

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### What is a man month?

by In reply to What is a man month?

For people working in the indusrial environment, a man-month is pretty well defined by some sort of agreement or custom. This is used in all person related costing. In the case of my company, it equals 208 hours. The reasoning is:

8 hr day (man day) x 6 day week = 48 hrs / week.
So 48 x 52 hrs / year.
So 48 x 52 / 12 = 208 hrs per month.

Another company I know of (into consulting) does a 40 hr week and their terms specify only a 40 hour week - with flexitime and transparency in reckoning 40 hrs / week.

For them a man month would be probably be 175 hrs and a man day would have no meaing.

So you see, you can frame it - both with your customers and employees. Be consistent.

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