Finish to Finish/Start to Start Dependencies with Lag.

This tip explains Lag with Dependencies other than Finish to Start, like Finish to Finish and Start to Start, in Microsoft Project 2013.

First we create a simple project:

Nenad Trajkovski FF-SS figure 1

As you can see in the Predecessors field, Tasks 1 and 2 have a Finish To Finish (FF) relationship, and Tasks 3 and 4 have Start To Start (SS) Dependencies. Now, suppose that Task 2 and Task 4 have two days of lag:

Nenad Trajkovski FF-SS figure 2

You get:

Nenad Trajkovski FF-SS figure 3

Task 2 will have a finish date of August 4, 2015 and will start two days later, so its start date is postponed!

When we repeat this for Task 4 we get:

Nenad Trajkovski FF-SS figure 4

The same result! The point to remember is that, yes, you can have Lag (and Lead) in tasks with dependencies other than Finish to Start, but be aware of consequences!

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Written by Nenad Trajkovski
MVP - Project Nenad Trajkovski was born in Zagreb in 1963. year. After completion of Faculty of Electrical Engineering, Nenad has started on the development and implementation of enterprise systems (ERP) in companies of various areas (banks, card houses, production companies, auto industry, wholesale businesses, oil companies, and others). He has extensive experience in working with business processes, people and knowledge in information technology and financial accounting activities. Currently, Nenad works as a consultant for the implementation of business systems, and as Project Manager. He is trainer for Project Management and Risk Management in Microsoft Innovation Center in Varaždin. At WinDays08 conference he has been declared as the best speaker, and his session as the best one. He was among TOP 10 speakers in the Microsoft Sinergija 2009 and at the Microsoft Vzija 2009. Shared first place as the best lecturer at KulenDays 2009 and the PMI Forum 2009 in Zagreb. Regular speaker at the Microsoft Community. On WinDays10 conference Nenad was among the top three speakers; at the conference Microsoft Vision 9 in Skopje between the top 5 speakers as well as on Microsoft Synergy 11 which was held in Belgrade. Certified Accountant, PMP (Project Manager Professional), PMI – RMP (Risk Manager Professional), MCP (Microsoft Certified Professional), MCTS – Microsoft Project 2010 (Microsoft Certified Technical Professional).  and MCT (Microsoft Certified Trainer).
1 Comment
  1. I actually prefer to put lags on SS or FF type of dependencies instead of using a FS with a Lead. However. You need to make sure you have a dependency that controls both ends of your task or the Critical Path may not be correct. Especially if you only use a SS dependency and don’t control the end of the task.
    An issue I have found with using SS or FF dependencies, the Task Inspector doesn’t work the way it should. Have you also found this to be true?

    great article. Thanks,

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