[kplato] PERT distribution/risk

[Jim Sabatke]

Dag Andersen wrote:
> Hi, need some guidance on this.
> 
> I find the following in the requirement spec:
> <quote>
> Durations are calculated for a task based on the resources assigned to 
> it. The following factors need to be taken into account:
> The effort required from each resource
> The risk associated with the resource/task pairing
> The availability schedule of each resource
> The other task commitments of resources
> 
> Note  [Jim Sabatke]
>   Allow task durations to be calculated from the following columns:
>  
>          "Optimistic Hours"    
>          "Pessimistic Hours"  
>          "Expected Hours"   
>          "Risk"    
>          "Duration"
>  
>          The "Duration" would be calculated like:
>  
>          "Risk" = Low        Duration = (OH + 4EH +PH) / 6
>          "Risk" = High      Duration = (OH + 4EH + 2PH) / 7
>          "Risk" = None      OH = EH = PH = "Duration"  
>  
>          If Duration is entered, then OH, PH, EH all will be set to 
>  "Duration" and "Risk = None"
> </quote>
> 
> It's the Risk that makes me uncertain. AFAICS it's a way to handle the 
> fact that some people are created more equal than others and hence, 
> that the time it takes to complete a task is dependent on the 
> specific resource(s) assigned to do the work.
> 
> Selecting a "High" risk thus effectively says: I don't think the 
> people assigned to this task is able to finish it within the normal 
> estimate, so I increase the estimate.
> 
> Also I think the risk must be interpreted to be for "resources 
> (plural)/task pairing" and not for "resource/task pairing" as stated 
> above? (Maybe what was meant anyway?)
> 
> IMHO it's not the estimate that should be modified but the efficiency 
> of the resource. To register this may be sensitive, though, and might 
> even be illegal in certain countries?
> 

I had spent a lot of time thinking on this subject.  One of the first 
things I noted is that resources are not only more equal than others, 
but more or less equal on the type of task.  For example: a resource 
might be much better at SQL coding than C++ than C than shell, etc.  I 
first thought that creating an inventory of resource skills might be a 
good idea and let the program assign risks.

The more I thought about that, the more I realized that maintaining that 
inventory set would be a huge task.  For example: a resource not good at 
SQL probably would improve significantly over the course of the project 
if assigned such work and mentored properly.  That means that learning 
curve would have to be included in the inventory.  You can see that it 
becomes very complex quickly.

Then you have the situation of highly motivated vs. unmotivated 
employees.  Some resources like to stand around and talk or surf the net 
more than work, at least in my experience.  Then sometimes they do 
quick, sloppy work to make the hours allotted.  I think this may be 
problematic for a resource inventory and probably where any legal 
questions might come in.

Finally I realized that project managers are there for a reason; to 
ensure that a project is properly planned, resourced and to 
control/motivate the resources as required.

I don't think it is unreasonable to assign a higher risk for 
inexperience; it's simply a fact of life.  You can assign lower risks to 
tasks for those employees as they get over the learning curve for the 
technology involved.  If you get stuck with a less motivated employee, 
you need to deal with that situation according to your own methods and 
company policies.

The key here is that KPLATO should not be a project manager.  It is a 
tool to plan, evaluate and communicate the progress of a project.

Thoughts, ideas??

Jim