Using "0/100" rule, and SPI

[new2vista]

I'd like to use the "0/100" rule, whereby a task is considered to be either 0
percent complete or 100 percent complete, but nothing in between. I know this
can be set (somewhat) in Tracking, but I'd like to use this rule and not have
it affect SPI negatively. So, for example, if a task takes 10 days to
complete, and I'm using the 0/100 rule, and we're at day 4 of this 10 day
duration, I don't want the SPI to say that we're 4 days behind schedule
because the task is 0 percent complete. I don't want SPI calculated until the
Finish date, at which time the task is (presumably) 100 percent complete.

Is there a way to get Project to do this? (I'm using Project 2003, if that
makes a difference).

Thanks.

 

[new2vista]

Well... the thought here is that in a complex plan, it helps to treat some
tasks as "atomic", in that their state is binary - they are complete, or not
complete. Hence, the 0/100 rule. Not all tasks in the plan would be treated
as such, only selected tasks. In that case, not calculating the SPI until the
task is complete makes sense, so I don't know that what I'm after is really
mutually exclusive.

I think I do agree with you that such "atomic" tasks would be short-term in
duration, or at least would be of a nature that it wouldn't make sense (or be
possible) to accurately estimate how much of the task is actually complete on
any given day. For instance, suppose the task is "Write the Statement of
Work". There's no way to guage accurately how much of the task is complete
from a content (or EV) perspective. You could say that "x of the total y
sections in the SOW pro forma are complete", and treat each section as a
subtask, if you want to go to that level of detail. But I believe that the
only tracking metric you could realistically use is that you've used 2 days
in the 5 days that the plan allows for this task to be completed, so you have
3 days left to get the work done. In some ways, this is a self-fulfilling
prophecy, since if you have 5 days to do the work, the work will take 5 days
to complete. But you wouldn't be able to say that on day 2, you have 38
percent of the SOW complete. Using the 0/100 rule in this case simplifies
tracking, but Project won't let you do that without negatively affecting the
SPI.

I am going to go out on a limb here, and suggest that you are trying to
achieve two mutually incompatible, mutually exclusive objectives.
You would choose a 0/100 approach to track because it is simple and low
maintenance but it comes at the cost of lower accuracy, which is acceptable
up to a point, or at least you choose to accept that the 0/100 ia accurate
enough.
In order for it to be reasonably accurate you must have Tasks with short
duration.

......

 

[Jim Aksel]

We trade accurracy for convenience. SPI=BCWP/BCWS. If BCWS is 0 or
non-existent, you are not penalized.

MS Project computs SPI correctly based on BCWS. If there is costed work
loaded into your baseline you are going to have SPI<1 on these 0/100 tasks.
So, to honor your request, you have to get BCWS out of the timephasing. You
can do that by loading 100% of your resources for the task on the last day of
the task and make it fixed duration of whatever lenght necessary. SPI now
brings the desired joy.

However, CPI=BCWP/ACWP. Since you cannot generate BCWP against no BCWS, you
are going to have CPI=0. If you post ACWP manually at intervals more
frequent than your tasks complete, well you've just traded one for the other.

Additionally, if you load resources into an inteval of "0" width you may
satisfy your SPI issue but look what you do to your man loading...

Consider short duration tasks as was suggested and weekly EV by the team.
You can delay your official reporting to month end, but the weekly EV coupled
with your 0/100 scheme will get you closer. This way, you'd only be carrying
the variance for 1 week if task durations are about 5 days or less.

I've been using the various methods of EV including 0/100 for years.
Generally, I explain I explain it like this- "Here are my contributors to the
SV and SPI<1. Of those, I am going to ignore those with EV method set to
0/100 where the Finish date is to the right of the Status Date. Now, lets
take a look at the other drivers..." I have checked with coworkers and we
show the same story using SAP, Cobra, and MPM. I can't speak for Open Plan
or Primavera.

It is pretty obvious what the contributors are to the low SPI, if they are
your 0/100 tasks then that is your explanation. Recognize this is a self
correcting problem. To me it is a matter of salesmanship to sell the
story... the agreed to method was 0/100 which causes the tool to produce an
SPI hit. Project has only one method of EV (linear %Complete).
--
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Jim
It''s software; it''s not allowed to win.

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