Duplicate GUIDs - Something that should not happen

Recently I got an email from a colleague at work.  He had a project file that he could not save in MS Project Server (MS PS.)   The file came from a vendor, it was not one he had built himself.  The error he got said that an error had occurred during the save process.  He could open the file, save it locally, but when he tried to save to PS, he got the same error repeatedly.  I first checked the PS queues and noticed that an error was being returned as he had mentioned.  I followed the link that showed me the error message details and noticed that the problem was a duplicate key in the Resource table and mentioned the GUID column.



GUIDs are fields that allow for complete uniqueness for each task and resource within a MS Project file and across all MS Project files within a system.  There is also the UID field that allows for uniqueness within a single MS Project file.  Refer to my earlier post on GUIDs and UIDs for more info. Titled - "UIDs, GUIDs - There are Druids in Project"


Since GUIDs are unique across the enterprise, I was surprised to learn that duplicates can happen.  Since the detailed error message mentioned the resource table, I went to the project file and applied the Resource Sheet view.  Fortunately, there were only about 20-30 resources in the view.  I did notice that there were a few resources with nothing in the Name column yet had the other relevant columns filled in, meaning that they were actual resources.  I then exposed the GUID column and sorted on it (this did not work well) and noticed that, sure enough, there were duplicates in the GUID column.  The duplicate resources did not have any assignments associated with them.  I decided to delete these resources and see what happened.  As you could predict, without the dups, I was able to save the project file into PS.


I then did some research on the web and found a few references to duplicate GUIDs.  GUIDs are used in other Microsoft products and they can be duplicated in the other products as well.  In Project desktop, the  GUIDs are not checked for uniqueness when the file is saved.  However, in MS PS, the GUIDs are checked for uniqueness when the file is saved into the PS repository.  Since the GUID column becomes a key in the Resource table and duplicates are not allowed, the error above is presented.


Since this file came from a vendor, I was not able to determine the exact situation that caused the duplication of the GUIDs.  The vendor is state that they built a project file that covered the work and then cloned the file 20 times, one for each location where the work would happen.  In talking with other experts, I learned that GUIDs can be duplicated by repeated copying and pasting of tasks or resources within MS Project. 

Dates and Calendars in MS Project

Dates and Calendars can be confusing within MS Project.  Recently, I have been asked some questions on them so I put together this presentation to explain how Dates and Calendars are stored and used.  I have uploaded a copy of my slides.  Feel free to review and use as you see fit.

In this presentation, I explain how Project (and other Office products) store dates and how date arithmetic is performed.  The types of Calendars and how they are used is also  covered.  I refer to MS Project 2010 & 2013 versions and also Project Server 2010 when they differ on Dates and Calendars.

Here is the link to the presentation:
https://drive.google.com/file/d/0B1X1zkrcPuSYVmJHRE5xbDd2RjQ/view?usp=sharing

Please comment if you want and respond with any questions, I will do my best to answer.

Thanks

UIDs, GUIDs - There are Druids in Project

Microsoft includes some columns in Project to help the user to keep track of things.  The Unique ID (UID) column is included to to uniquely identify a task within a Project file. The GUID column uniquely identifies a task across all files.  Both can be very useful when needed.

Using the Compare feature of Microsoft Project.

One of the most useful features of MS Project I have found is the Compare feature.  Compare is as you can guess, it compares one .mpp file with another.  This is most useful when comparing two versions of the same file. The Compare feature is in Project 2010 and 2013.  Project 2007 does not have a Compare feature.  Project 2003 has a Compare, but it was removed in 2007.  I have learned recently that there are situations where the Compare feature does not work in 2013.  The fix seems to be to ensure that the Microsoft Patches are applied.

Why does Project move my tasks around when I assign a resource?


Some time ago, one of my colleagues came to me with a problem.  He was updating a MS Project schedule (plan) by adding resources to the project tasks and every time a resource was added to the task, Project would physically move the task up or down in the schedule.  This of course was very frustrating and wreaked havoc on the schedule.  For Example; Adding a resource to the task in the 4th row, would move the task to the 10th row and renumber the Work Breakdown Structure (WBS) number and the ID number.  It would also shift to another Summary task.  Not a good thing.

I am often a asked questions on how Project works.  I have used it for more than 20 years and over time I have become an expert.  I often say that Project is un-intuitive and this case is a good example.  "Why is Project moving my tasks around?" was his question to me.  "I have never had this happen before."  He added.

It took a while to find the answer.  As I usually do, I asked for a copy of the file and went off by myself to investigate.  I remembered that within Project one can sort on any column that one want to.  When I checked the file sure enough, someone had sorted the file on the resource column.  As resources were added Project would rearrange the tasks in Resource name order.  Once I resorted the file using the ID column, everything worked fine.  Resources could be added without changing the sequence of the tasks.  My colleague was very happy.  Here is an image of the fix.

First insert the ID column if it is not in the table and view.  Then click on the down arrow at the top of the ID column and select "Sort smallest to largest" option - circled below.  This will resolve the issue.

I offer this post as a help to other users of Project.  I have learned a lot of what I know about Project the hard way; by making mistakes and trying different things.  Project can be unintuitive, so remember that the learning curve is long and steep at times.