Early/Late Start and Finish Dates

[Sourabh Dasgupta]

I am using MS Project 2002. Can somebody explain how to calculate the
early/late start and finish dates for tasks? When I first create the tasks
these early/late start & finish dates are same as the planned dates. How are
these constraints set and calculated as project progresses?

 

[Mike Glen]

Hi Sourabh ,

Welcome to this Microsoft Project newsgroup

The dates are calculated by Project using the principles of Critical Path
Analysis. You can see how this is done in my series on Microsoft Project in
the TechTrax ezine, particularly #1, at this site: http://tinyurl.com/2xbhc
or this:
http://pubs.logicalexpressions.com/Pub0009/LPMFrame.asp?CMD=ArticleSearch&AUTH=23
(Perhaps you'd care to rate the article before leaving the site,
Thanks.)

Remember to never type in dates. Project works on your input of Duration
and Precedence links. It then does what it is designed to do and that is to
calculate the date giving you a schedule based on what's possible. Any
dates you type in will cause constraints to be created which will reduce the
flexibility of your project.

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

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

Mike Glen
MS Project MVP

 

[Sourabh Dasgupta]

Thanks a lot Trevor

Early and late dates will be the same if you have no network at all or if
you have just a single path through all of the Tasks from start to finish,
or if there are multiple paths all of the same overall duration.
A Task with the early and late dates equal has Float and is a Critical Task.
A Task with the early and late dates not equal has Float and is a
Non-critical Task.
ES, EF, LS, LF are determined by the Tasks durations and their positions in
the network, ie the way they are related by their dependency or predecessor
links.
The forward and backward pass calculation performed by MSP find the ES, EF,
LS, LF.

Obviously, there is a lot more to it but that's the basics.

Try this with Tasks A - E. Give them durations and links as shown. Don't
type any dates.

2 A 10 days 02/07/07 13/07/07
3 B 12 days 16/07/07 31/07/07 2
4 C 5 days 16/07/07 20/07/07 2
5 D 5 days 23/07/07 27/07/07 4
6 E 5 days 01/08/07 07/08/07 3,5

Trevor RabeyTrevor Rabey 0407213955 61 8 92729485 PERFECT PROJECT PLANNING
www.perfectproject.com.au

 

[Sourabh Dasgupta]

Thanks Mike. It helped.

Hi Sourabh ,

Welcome to this Microsoft Project newsgroup

The dates are calculated by Project using the principles of Critical Path
Analysis. You can see how this is done in my series on Microsoft Project in
the TechTrax ezine, particularly #1, at this site: http://tinyurl.com/2xbhc
or this:
http://pubs.logicalexpressions.com/Pub0009/LPMFrame.asp?CMD=ArticleSearch&AUTH=23
(Perhaps you'd care to rate the article before leaving the site,
Thanks.)

Remember to never type in dates. Project works on your input of Duration
and Precedence links. It then does what it is designed to do and that is to
calculate the date giving you a schedule based on what's possible. Any
dates you type in will cause constraints to be created which will reduce the
flexibility of your project.

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

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

Mike Glen
MS Project MVP

 

[Mike Glen]

You're welcome, Sourabh

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