MANAGERPORT®: Your harbour for professional management growth
Join the community. Share your wisdom - lessons Lesson or link Link or a question Question .
Back to List
Question
35

person month

by Frantisek Babic

Sometimes, the students have a problem to understand this concept, especially its practical application on their student's works during the course Project management. They propose own projects like to solve a problem of campus navigation using a mobile app or to build mobile bike stations aiming to reduce the traffic density. Is there a simple explanation of this issue?

Upvote post

4 Comments

  1. This term seemed uncommon to me, but then i have found out that it is a politically correct synonym for man-month. I'm wondering when thay start using "personpower" instead of manpower... Anyway, i would explain man-month or person-month as a measurement unit for effort (work) required to complete a task or project. 1 man-month means amount of work performed by the average worker (e.g. programmer) in one month. In project it is mainly used for cost estimation. For example if the effort (work) required to complete the project is 8 man-months, then the project will spend 8xaverage monthly labor cost, regardles of number of workers (it can be 4 workers for 2 months, 2 workers for 4 months, etc.). When estimating the required effort in reality also the non-productive overhead (for communication, issue resolving, ...) has to be considered, which can be for example 20%. So if the "net effort" required for project completion is 8 man-months, then the actual project costs will be 10 man-months.
    +3 Reply Upvote post

  2. More frequently is used manday. This is an unit for calculating effort and measuring performance in project planing and project execution & control. If it was estimated that a work package needs f.e. 100 manday, it means to have this work package finished we need 100 days of work of one person or two people each by 50 days ... It does not mean exactly, that the work package will be automatically finished in 100 days, but the necessary effort will be 100 days (or 800 hours).
    +2 Reply Upvote post

  3. Maybe simple explanation is: A “person month” is considered as the metric for expressing the effort (amount of time) personnel devote to a specific project. As example: 20% of a 12 month calendar equals 2.4 calendar year person months, i.e. 12 x 0.20 = 2.4). More practical in client projects is being used MD to estimate the effort and the cost for either whole solution or individual products or resources. In case of MD the other important factor to calculate total cost is the MD rate for required resource. e.g. for Senior PM or Architect should be expected higher cost than for some junior resource. When students intent to build the app or bike station they also need to understand the effort they spend and this can be from project view calculated as MD effort and eventually to evaluate the cost.
    +2 Reply Upvote post

  4. Thanks for all answers.
    +1 Reply Upvote post

Forgot Password?

Don’t have account? Register here!

Please read the Terms of Use and Privacy Notice

User Agreement:
Check here to indicate that you have

We have sent an email with a confirmation link to your email address. In order to complete the registration, please click the confirmation link.

​

The link expires within the next 14 days.

Please check, whether the email is in the junk folder, since confirmation mails with backlinks are sometimes classified as spam.

Please press the button.
Save All Changes.