Tasks do not start asap

[Claus33]

I had to implement a number of changes into an existing project plan (arround
1000 tasks). After number od optimizations, I noticed that a number of tasks
were shifted to later dates. All of them are succesors of other tasks and
their constraint is "start as soon as possible". I can not recognize any
reason, why these tasks do not start directly after their predeccesors. Their
are no constraints like "Must start at" etc. and there are no values
calculated (e.g. "work done" etc.).

I found only a trick to move these tasks to the "as soon as
possible"-position:
First I have to change their status to ""Must start at" and directly after
this setting I have to set them back to "Start as soon as possible". After
this "trick", these tasks are starting at the desiered dates ("as early as
possible").

How van I avoid such cumbersome corrections?

Regards
Claus

 

[Dale Howard [MVP]]

Claus33 --

If you are using Microsoft Project 2007, you can use the Task Drivers tool
to learn why the software has scheduled the Start date of any task. Factors
include:

Dependencies on predecessor tasks, including Lag or Lead time
Constraints
Calendars (project, resource, or task)
Leveling Delays
An Actual Start date (entered intentionally or accidentally)

To use this feature, click Project - Task Drivers and then select a task of
interest. If you are using an earlier version of Microsoft Project, this
feature is not available. In that case, I would take a serious look at the
third, fourth, and fifth factors I mention in the list above. Hope this
helps.

 

[Claus33]

Dale,

thank you for your fast reply.

I am using Project 2003 - so the Task Driver Tool will not help me.

I have checked all the factors you mentioned:

- there are no dependencies on predecessor tasks, including Lag or Lead time
- there are no constraints
- there are no calendar influences
- there are no actual Start dates
- ? Leveling Delays - I do not think this could be the reason, because most
of the tasks have no ressources assigned.

I do not understand, why my "trick" works - perhaps this is the key to
understand the problem. To repeat it: Changing the tasks to "Must start at"
and then rechanging them immediately afterwards to "Start as soon as
possible" solves the problem. It is a cumbersome method, but it moves the
tasks to the "As soon as possible" position? What could explain this behavior?

Regards
Claus

 

[Dale Howard [MVP]]

Claus33 --

Click Project - Project Information. Out of curiosity, is the project
scheduled from a Start date or a Finish date? Let us know.

 

[Jack Dahlgren]

Also try tools menu / options / calculation tab and make sure it is set to
"automatic"

-Jack Dahlgren

 

[Claus33]

Dale,

the setting was "Schedule from start date" - so this can not be the reason.

I did some further investigations. The problem seems indeed to depend from
tasks with assigned ressources or tasks depending from such ressource-bound
tasks. When the plan showed the not-asap starting tasks, the resources were
leveled to <=100% workload. My "trick" (setting each such task to "Must start
at ..." and reset afterwards to "Start as early as possible") brought back my
original planning. Also the ressources are now overloaded again, because they
are sometimes used two or more times.

After better understanding the problem now, I can define my request better:
I would like to apply resources, to use the calendar for consideration of
individual vacation days. In spite of that, I would not like to see any
influence on start/end dates, if the resources are used multiple times in the
same time frame (because their tasks are not really working time-based).

So the following questions remain:

a) Is their a way, to use resources in this way (using calendar but no
leveling work load)?
b) Is their a way, to recalculate a complete plan at once to remove the
leveling and to have unbalanced/overloaded resources again?

Regards
Claus

 

[Dale Howard [MVP]]

Claus --

Have you added your company holidays as nonworking time to the Standard
calendar in your project? Click Tools - Change Working Time and look
through the calendar for your company's holidays. If you don't see them,
then add them as nonworking days. Assuming the Standard calendar is still
set by default as the Project calendar (Project - Project Information) and
you have specified the Standard calendar as the Base Calendar for each
resource in the project (View - Resource Sheet), then the software will
schedule each task according to your company holidays. Also, you can add
vacation time as nonworking time to each resource's calendar by
double-clicking the resource's name in the Resource Sheet view and then by
adding the nonworking time on the Working Time page in the Resource
Information dialog. This will cause Microsoft Project 2003 to reschedule
work around each resource's vacation on any task originally scheduled during
the vacation time period.

Based on your description of the original problem, it sounds like somebody
leveled resource overallocation in the project. Click Tools - Level
Resources and make sure that leveling is set to Manual and not to Automatic.
If you want to remove all Leveling delays in the project, apply any task
view, click Tools - Level Resources, and then click the Clear Leveling
button. Hope this helps.

 

[meg99]

One other thing to check is summary predecessors. If a summary task
is a predecessor you will get what you described.

meg99

 

[Steve House]

If resource leveling is set to automatic (Tools, Resource Leveling dialog)
and you do something that creates a resource overallocation, the system will
immediately move the task to resolve the resource issue. I suspect that is
what is happening here. Go to the leveling tool in the menu and verify it
is set to 'manual' so it won't trigger until you explicitly request it.

--
Steve House [Project MVP]
MS Project Trainer & Consultant
Visit http://project.mvps.org/faqs.htm for the FAQs