[Planner] Resource dependencies

[Brian Christensen <brian SimpleProjectManagement com>]

Sheldon,

> I'm trying out Planner for the first time today. It seems to work very 
> well so far, but I have a
> question. Is there any way for Planner 0.11 to implement dependencies 
> between tasks based on
> (work) resource availability, or do I just have to manually create 
> task dependencies?
>
> Just in case I'm not sufficiently clear, I have a situation where one 
> "startup" task is a
> predecessor of about 8 different tasks that are logically parallel. 
> However, all of the tasks are
> assigned the same resource at 100% and Planner seems to be perfectly 
> happy scheduling all of the
> tasks simultaneously, although the resource can't actually work at 
> 800% to do all of them in
> parallel.

This question goes back to the definition of what a dependency is. Most 
of the books say that a task A is dependent on a task B if task B can't 
start until task A is finished. However, even though the tasks are 
logically parallel, if the same person is going to do both tasks, that 
person will almost always have a preference in the order they are done. 
It is convenient to treat the tasks "as if" they were dependent and to 
define dependencies between them.

It is better to define a "treat them as if" dependency than to let the 
tool define a random order for the tasks. This shows up most clearly 
when you are taking status from the team. Say your team member has been 
assigned tasks A, B, and C. that are logically parallel and so can be 
done in any order.  Let's assume that the tasks will each take a week 
to complete. You let the computer assign an arbitrary order to the 
tasks and it comes up with C then B then A. What does your status look 
like if the person decides to complete task A first? You would have to 
report that task C is late and task A is early. You would also have to 
explain to your management and to your customer why it is not a problem 
to have a late task. Why create problems for yourself that can be 
avoided?

If the tasks are relatively small there is another approach you can 
use. If you plan on taking status weekly and the three tasks together 
would take a week or less to complete, combine them into one larger 
task. Then you have only one task to schedule and assign. The fact that 
the pieces of the larger task can be completed in any order stops being 
a scheduling concern.

Speaking of enhancements to planner. Instead of an algorithm that 
schedules tasks based on resource availability, it would be more useful 
(and easier to implement) if planner would allow the scheduler to enter 
both "hard" and "soft" (or "as if") dependencies. They could be treated 
the same by the scheduling algorithm, but the distinction would help 
the project manager to keep track of which is which.

-- Brian Christensen

P.S. Sheldon, would it be okay with you if I quote your question on my 
web page?
----------------------------------------------------------
http://www.SimpleProjectManagement.com
(What everyone in your organization needs to know about project 
management.)