A potential gotcha with manually scheduled tasks…

One of the new features introduced in Project 2010 is manual scheduling. Prior to 2010, all project tasks were automatically scheduled, meaning that as soon as you put it in the schedule, MS Project would try and schedule it for you. Whilst most people get used to this behaviour, others prefer more control over the schedule, hence why manual scheduling was introduced. This feature allows the user to enter tasks where they want in the WBS and not have to provide meaningful duration or work data for the task to be scheduled.

For instance, if you are planning a project and know it will consist of six phases, but you are a little unsure of how long the phases are going to take, you could create six manually scheduled tasks on a plan representing each phase.


Notice that the work, duration and Start and Finish columns have not been populated as they would have normally. We can now start to put the information we know about the tasks into the plan, including rough start and end dates where known, but more importantly we can record other textual information that previously would have either been maintained outside of the plan, or hidden in notes fields.

Manual Scheduled Tasks

In order to support this new feature, Microsoft have created a number of new fields behind the scenes, and renamed a few others:

Pre 2010 Field 2010 Field Comment
Duration Scheduled Duration New name for the pre 2010 Duration column
Start Scheduled Start New name for the pre 2010 Start column
Finish Scheduled Finish New name for the pre 2010 Finish column
Duration New Project 2010 field that stores duration information, but also allows text entry
Start New Project 2010 field that stores Start date information, but also allows text entry
Finish New Project 2010 field that stores Finish date information, but also allows text entry

You can see from the screenshot below, what these fields look like for the example I used above:

Manual Schedule

For task 1, we entered a duration of 4 days, so Project has determined the scheduled duration will be 4 days also, it has also determined the scheduled start date to be the 17th Feb, the current start date of the project, even though we have entered TBC in the Start field. Likewise the scheduled finish date is 4 days later, even though the finish field is blank.

For task 2, the scheduled start is still the 17th Feb, even though we have put a start date of the 18th in the start field. Now this behaviour is slightly different to what I would have expected. Given a date has been supplied, I would have expected the scheduled date to respect that, but the project start date has been picked up again as it would if it was automatically scheduled and had no predecessor. The concern is that if this schedule was saved in Project Server 2010,  the Scheduled Start and Scheduled Finish fields will move into the Project Server Reporting database and are translated to the Start and Finish fields, so there is the potential for the reports to be showing different information compared to what is being displayed in the Project user interface.

Manual Tasks - SQL Query

You can see above that the TaskStartDate is in fact the ScheduledStart field and that the Start field is in fact the TaskStartDateString.

What this means is that if you have a report that references TaskStartDate, the data contained within the field will be the Scheduled Start and not the Start as you would expect.

If this is indeed the designed behaviour of the tasks and not a quirk of the Release Candidate, then this is a very important consideration for organisations that are looking at using manually scheduled tasks with Project Server 2010.

2 thoughts on “A potential gotcha with manually scheduled tasks…

  1. Hi Alex, Came across your site from LinkedIn. Some gr8 content here. Like the links to MVP’s and blogs on the right. This particular post is interesting. Have you have any further developments from it? Is it a fact that the data can be out of synch? (good spot sir!)

  2. I think the behavior might change if you select Project Schedule Options from the Backstage view, and check the box for “Keep tasks on nearest workign day…” as this results in a constraint if you change to AutoSchedule, versus dropping back to the start date if you dont have it checked. You should see a similar impact here.

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