Hard Constraint vs. Deadline – Guest blog

Introducing my second guest blogger: Nenad Trajkovski from the blog: http://ntrajkovski.com/. Nenad has been one of my favorite bloggers since I started working with MS Project years ago. I have retweeted a number of his very interesting blog posts on numerous occasions. He has a great style of blogging where he uses easy to understand images more than he uses words. So when we bumped into each other at the Project Conference 2014 I just had to ask if he was willing to do a guest post on my blog. Because my post on date related planning has seen some high attention lately I wanted to ask Nenad to share his view on the matter. Without further ado, here is his post.

Hard constraint vs. Deadline

Suppose that you want to know when you have exceeded your project finish data. Here is the sample Project:

A sample project used in this blogpost.

Now suppose that you want your house to be finished at Wednesday, 09.04.2014. You can set: Must finish on constraint on the Milestone: House is finished:

A picture showing how to add a must finish on constraint in Microsoft project

And you will get:

A planning wizard menu telling the user that a constraint is placed on the task.

This is a warning that tells me about a potential Schedule conflict, but I decided to go on with this Constraint. Now, suppose that “The roof” needs 4 days to finish instead of three days:

The planning wizard in Microsoft Project.

I get another warning this time it tells me there will be a schedule conflict, but I decided to go on. So I get:

A constraint is causing a planning conflict.

A better approach

As you can see, this scenario doesn’t make sense, because “The roof” will be finished at Thursday 10.04.2014, and the house will be finished one day before (Wednesday, 09.04.2014), which is nonsense. Hard constraints should be avoided. I will now return to my previous scenario without Constraint:

A sample project used in this blogpost.

And I will make Wednesday, 09.04.2013, as Deadline:

A picture describing the steps that need to be taken to set a deadline on a task. using Microsoft Project 2013.

And I’ll get:

A picture highlighting the deadline visualisation in MS Project.

Now, again suppose that roof need 4 days to finish instead of three days:

A milestone that passes the deadline set date.

My project will be (and it WILL BE), late, and I’ll get a warning message in Info column about that. This is much better approach!

Final notes

Hi Readers it’s me again, Erik. I hope you enjoyed the post about Deadlines being a better option than setting hard constraints like “must finish on” and “start no earlier than”. For my clients the approach of using deadlines has always resulted in a better understanding of the product.

And just like Bonnie, I would welcome back Nenad any time to do another guest post! Here is his own blog again, for good reference, drop him a line and say you read our blog, he will love that: http://ntrajkovski.com/