Number of working days in a month

[ks2008]

Refer the problem and the solution below. Here is my question.

Most Pessimistic = One month

How can you assume 20 is the # of working days for a month ?

Problem:
You are given the following information about a specific task’
duration:
Most Optimistic = 8 days
Most Pessimistic = One month
Expected = 3 weeks
Using the formula for Estimated Duration, how many days can you expec
the task to take? (It’s not the Expected Duration!)

Solution:
Before you began, you should have changed the Most Pessimistic time t
20 days and the Expected time to 15 days. When working a mathematica
equation such as this, it’s imperative to use the same units of tim
(that is, you never mix months with days in the same equation). Tha
being said, because Estimated Duration = (Optimistic + Pessimistic
(4*Expected))/6, plugging in the numbers offers the following for th
Estimated Duration:
= ((8 + 20 + (15*4))/6
= ((28 + (15*4))/6
= (28 + 60)/6
= 88/6
= 14.67 day

 

[Jan De Messemaeker]

The estimators who say 1 month must have had a number of days in mind.
People do not work months, but hours.
So if it's not 20, ask the estimators what they mean.
HTH

--
Jan De Messemaeker
Microsoft Project Most Valuable Professional
+32 495 300 620
For availability check:
http://users.online.be/prom-ade/Calendar.pdf

 

[Mike Glen]

Hi ks2008,

Welcome to this Microsoft Project newsgroup

In Tools/Options.../Calendar tab, you will see the default number of working
days in a month is 20, the same as 4 weeks.

FAQs, companion products and other useful Project information can be seen at
this web address: http://project.mvps.org/faqs.htm

Hope this helps - please let us know how you get on

Mike Glen
MS Project MVP
See http://tinyurl.com/2xbhc for my free Project Tutorials

 

[Eric B]

To install the Analysis toolbar, manually turn off the COM add-ins use
by the toolbar, and then turn them back on.

1. On the View menu, point to Toolbars, and then click Customize.
2. Click the Commands tab.
3. In the Categories box, click All Commands.
4. In the Commands box, click the ComAddInsDialog command and dra
it to one of the toolbars currently displayed in the Project window.

For example, click the ComAddInsDialog command and drag it to th
end of the Standard toolbar.

A line appears on the toolbar, indicating where the button fo
the command will be placed. Release the mouse button to add th
ComAddInsDialog command to the toolbar.
5. Click Close on the Customize dialog box.
6. Click COM Add-Ins on the toolbar where it was added.
7. Clear the check boxes for the Adjust Dates, Copy Picture t
Office, and PERT Analysis add-ins, and then click OK.
8. Click COM Add-Ins again.
9. Select the check boxes for the Adjust Dates, Copy Picture t
Office, and PERT Analysis add-ins, and then click OK.
10. On the View menu, point to Toolbars, and then click Analysis t
display the Analysis toolbar

 

[Ammar Al-Saket]

Hi Mike,
A simple calculation shows that 1 month equals (Approx. & in Aver.) 4.3
weeks or 21.5 working days, why not to use this as a standard in order to
correspond to the fact that a year is consists of 12 months. What do you
think and how that can affect several years project length.

Thanks in advance

 

[Ammar Al-Saket]

Obviously, my previous post is based on an assumption that a week includes 5
working days!

 

[Mike Glen]

Hi AS,

You are right, but it's up to you to specify how many days you want to
define as a month. Project defines it as 20 days - that was the designers'
choice.

Mike Glen
Project MVP
See http://tinyurl.com/2xbhc for my free Project Tutorials

 

[Steve House]

However it's only a conversion factor for duration input and display.
Inputting durations in months is such a coarse estimate of task duration
that any errors introduced by using 20 instead of 21.5 are totally trivial,
of no consequence., If you need more precision, enter durations in smaller
units such as weeks, days, or hours.