PERT Automation Using VB

[YBatsh]

I'm working on a project that includes project automation. I'm been asked to
include calculations of durations according to optimistic / pessimistic
ratios using PERT. Does MS Project automation allow for interaction with PERT?

 

[Ed Morrison]

When I used the PERT toolbar while recording a macro, I didn't get any code.
So I don't know if there is an explicit object to call.

However, you could do the calculations manually. PERT uses the durations in
Duration1, 2 and 3 for Optimistic, Expected, and Pessimistic. It then
figures out the start/finish dates for each option and puts them into
Start1/Finish1, Start2/Finish2, and Start3/Finish3. The task's duration is
calculated using the default weighting of 1x the Optimistic Duration, 4x the
Expected duration and 1x the Pessimistic duration. Of course you could
change the weighting, but in order to keep with Microsoft's PERT rule, the
sum of the multipliers must equal 6.

Hope this helps.

 

[Brian K - Project MVP]

When I used the PERT toolbar while recording a macro, I didn't get any
code. So I don't know if there is an explicit object to call.

However, you could do the calculations manually. PERT uses the durations
in Duration1, 2 and 3 for Optimistic, Expected, and Pessimistic. It then
figures out the start/finish dates for each option and puts them into
Start1/Finish1, Start2/Finish2, and Start3/Finish3. The task's duration
is calculated using the default weighting of 1x the Optimistic Duration,
4x the Expected duration and 1x the Pessimistic duration. Of course you
could change the weighting, but in order to keep with Microsoft's PERT
rule, the sum of the multipliers must equal 6.

Hope this helps.

Along those lines here is an article I wrote a while back about doing a
VBA macro that allowed you to do PERT with Work values instead of
Durations. It might help out a bit.

http://techrepublic.com.com/5100-6315_11-1038873-1-1.html

 

[Yasser M. Batsh]

Thank you Ed and Brian for your valuable answers. It seems after all that i
have to do the calculations manually and use the formulas u provided to
calculate the PERT durations / dates.

 

[Yasser M. Batsh]

Just one more question fellows. The purpose for using PERT in my project is
to provide the ability to crash a certain project to meet some deadline.
Crashing the project will make use of the PERT durations [optimistic /
pessimistic ..] to see if the project can make it for the new deadline.
Taking into account that we have dependencies between tasks in the project,
manual calculations of the PERT crashed timeline would not be that easy!!
Any Clues???

 

[Ed Morrison]

Calculate the duration of the tasks. Duration is not dependent on task
linkage.
--
Ed Morrison
msProjectExperts
"We wrote the books on Project Server"
http://www.msprojectexperts.com
FAQ - http://www.projectserverexperts.com

Just one more question fellows. The purpose for using PERT in my project
is
to provide the ability to crash a certain project to meet some deadline.
Crashing the project will make use of the PERT durations [optimistic /
pessimistic ..] to see if the project can make it for the new deadline.
Taking into account that we have dependencies between tasks in the
project,
manual calculations of the PERT crashed timeline would not be that easy!!
Any Clues???

 

[Yasser M. Batsh]

I agree with you on this point. What i would do then is to calculate the PERT
durations manually in my program and then when i want to crash my project i
supply MS project with PERT optimistic duration and see if it can meet the
deadline.

Calculate the duration of the tasks. Duration is not dependent on task
linkage.
--
Ed Morrison
msProjectExperts
"We wrote the books on Project Server"
http://www.msprojectexperts.com
FAQ - http://www.projectserverexperts.com

Just one more question fellows. The purpose for using PERT in my project
is
to provide the ability to crash a certain project to meet some deadline.
Crashing the project will make use of the PERT durations [optimistic /
pessimistic ..] to see if the project can make it for the new deadline.
Taking into account that we have dependencies between tasks in the
project,
manual calculations of the PERT crashed timeline would not be that easy!!
Any Clues???

:

When I used the PERT toolbar while recording a macro, I didn't get any
code.
So I don't know if there is an explicit object to call.

However, you could do the calculations manually. PERT uses the
durations in
Duration1, 2 and 3 for Optimistic, Expected, and Pessimistic. It then
figures out the start/finish dates for each option and puts them into
Start1/Finish1, Start2/Finish2, and Start3/Finish3. The task's
duration is
calculated using the default weighting of 1x the Optimistic Duration,
4x the
Expected duration and 1x the Pessimistic duration. Of course you could
change the weighting, but in order to keep with Microsoft's PERT rule,
the
sum of the multipliers must equal 6.

Hope this helps.
--
Ed Morrison
msProjectExperts
"We wrote the books on Project Server"
http://www.msprojectexperts.com
FAQ - http://www.projectserverexperts.com



I'm working on a project that includes project automation. I'm been
asked
to
include calculations of durations according to optimistic /
pessimistic
ratios using PERT. Does MS Project automation allow for interaction
with
PERT?

 

[Ed Morrison]

Yes, that should work. Just a word of caution... your optimistic durations
may not reflect reality and they may give your stakeholders a false sense of
security. We use PERT because it is a good way of estimating duration.
Sometimes things go well, so times they don't go well, but usually they go
as expected (about 66% of the time according to PERT). We can never expect
tasks to go well every time.

You can crash your plan using more realistic (aka less optimistic) ways such
as adding resources to effort drive tasks, increasing working time,
assigning more experienced resources, eliminating slack, etc.


--
Ed Morrison
msProjectExperts
"We wrote the books on Project Server"
http://www.msprojectexperts.com
FAQ - http://www.projectserverexperts.com

I agree with you on this point. What i would do then is to calculate the
PERT
durations manually in my program and then when i want to crash my project
i
supply MS project with PERT optimistic duration and see if it can meet the
deadline.

Calculate the duration of the tasks. Duration is not dependent on task
linkage.
--
Ed Morrison
msProjectExperts
"We wrote the books on Project Server"
http://www.msprojectexperts.com
FAQ - http://www.projectserverexperts.com



message

Just one more question fellows. The purpose for using PERT in my
project
is
to provide the ability to crash a certain project to meet some
deadline.
Crashing the project will make use of the PERT durations [optimistic /
pessimistic ..] to see if the project can make it for the new deadline.
Taking into account that we have dependencies between tasks in the
project,
manual calculations of the PERT crashed timeline would not be that
easy!!
Any Clues???

:

When I used the PERT toolbar while recording a macro, I didn't get
any
code.
So I don't know if there is an explicit object to call.

However, you could do the calculations manually. PERT uses the
durations in
Duration1, 2 and 3 for Optimistic, Expected, and Pessimistic. It
then
figures out the start/finish dates for each option and puts them
into
Start1/Finish1, Start2/Finish2, and Start3/Finish3. The task's
duration is
calculated using the default weighting of 1x the Optimistic
Duration,
4x the
Expected duration and 1x the Pessimistic duration. Of course you
could
change the weighting, but in order to keep with Microsoft's PERT
rule,
the
sum of the multipliers must equal 6.

Hope this helps.
--
Ed Morrison
msProjectExperts
"We wrote the books on Project Server"
http://www.msprojectexperts.com
FAQ - http://www.projectserverexperts.com



I'm working on a project that includes project automation. I'm
been
asked
to
include calculations of durations according to optimistic /
pessimistic
ratios using PERT. Does MS Project automation allow for
interaction
with
PERT?

 

[Yasser M. Batsh]

So far so good. But still there is one more obstacle in the way. We are using
the PERT durations to see if we can meet a certain deadline, however in our
custom implementation we don't have the PERT way in prioritizing which tasks
to invlolve to reach that deadline. That is, one task crashed to its
optmistic duration can be enough to reach my deadline; but how can i identify
this task; i can have many combinations to reach the deadline!!
How does PERT do it ?

Yes, that should work. Just a word of caution... your optimistic durations
may not reflect reality and they may give your stakeholders a false sense of
security. We use PERT because it is a good way of estimating duration.
Sometimes things go well, so times they don't go well, but usually they go
as expected (about 66% of the time according to PERT). We can never expect
tasks to go well every time.

You can crash your plan using more realistic (aka less optimistic) ways such
as adding resources to effort drive tasks, increasing working time,
assigning more experienced resources, eliminating slack, etc.


--
Ed Morrison
msProjectExperts
"We wrote the books on Project Server"
http://www.msprojectexperts.com
FAQ - http://www.projectserverexperts.com

I agree with you on this point. What i would do then is to calculate the
PERT
durations manually in my program and then when i want to crash my project
i
supply MS project with PERT optimistic duration and see if it can meet the
deadline.

Calculate the duration of the tasks. Duration is not dependent on task
linkage.
--
Ed Morrison
msProjectExperts
"We wrote the books on Project Server"
http://www.msprojectexperts.com
FAQ - http://www.projectserverexperts.com



message
Just one more question fellows. The purpose for using PERT in my
project
is
to provide the ability to crash a certain project to meet some
deadline.
Crashing the project will make use of the PERT durations [optimistic /
pessimistic ..] to see if the project can make it for the new deadline.
Taking into account that we have dependencies between tasks in the
project,
manual calculations of the PERT crashed timeline would not be that
easy!!
Any Clues???

:

When I used the PERT toolbar while recording a macro, I didn't get
any
code.
So I don't know if there is an explicit object to call.

However, you could do the calculations manually. PERT uses the
durations in
Duration1, 2 and 3 for Optimistic, Expected, and Pessimistic. It
then
figures out the start/finish dates for each option and puts them
into
Start1/Finish1, Start2/Finish2, and Start3/Finish3. The task's
duration is
calculated using the default weighting of 1x the Optimistic
Duration,
4x the
Expected duration and 1x the Pessimistic duration. Of course you
could
change the weighting, but in order to keep with Microsoft's PERT
rule,
the
sum of the multipliers must equal 6.

Hope this helps.
--
Ed Morrison
msProjectExperts
"We wrote the books on Project Server"
http://www.msprojectexperts.com
FAQ - http://www.projectserverexperts.com



I'm working on a project that includes project automation. I'm
been
asked
to
include calculations of durations according to optimistic /
pessimistic
ratios using PERT. Does MS Project automation allow for
interaction
with
PERT?

 

[Ed Morrison]

How do you have Project do this automatically now? I know that we can show
the Optimistic Gantt, but this uses all Optimistic durations.

My guess is to look for the task on the critical path with the biggest
difference between the optimistic duration and the duration you are using.
Crash this task.

To automate it, you could have a button that crashes one task at a time.
The code could check each task on the critical path, find the biggest
duration difference and use the optimistic duration. Make sure to alert the
PM as to which task was crashed. If the change isn't big enough for the PM,
run it again. Of course the critical path may have changed.

Let us know how this works.

--
Ed Morrison
msProjectExperts
"We wrote the books on Project Server"
http://www.msprojectexperts.com
FAQ - http://www.projectserverexperts.com

So far so good. But still there is one more obstacle in the way. We are
using
the PERT durations to see if we can meet a certain deadline, however in
our
custom implementation we don't have the PERT way in prioritizing which
tasks
to invlolve to reach that deadline. That is, one task crashed to its
optmistic duration can be enough to reach my deadline; but how can i
identify
this task; i can have many combinations to reach the deadline!!
How does PERT do it ?

Yes, that should work. Just a word of caution... your optimistic
durations
may not reflect reality and they may give your stakeholders a false sense
of
security. We use PERT because it is a good way of estimating duration.
Sometimes things go well, so times they don't go well, but usually they
go
as expected (about 66% of the time according to PERT). We can never
expect
tasks to go well every time.

You can crash your plan using more realistic (aka less optimistic) ways
such
as adding resources to effort drive tasks, increasing working time,
assigning more experienced resources, eliminating slack, etc.


--
Ed Morrison
msProjectExperts
"We wrote the books on Project Server"
http://www.msprojectexperts.com
FAQ - http://www.projectserverexperts.com



message

I agree with you on this point. What i would do then is to calculate the
PERT
durations manually in my program and then when i want to crash my
project
i
supply MS project with PERT optimistic duration and see if it can meet
the
deadline.

:

Calculate the duration of the tasks. Duration is not dependent on
task
linkage.
--
Ed Morrison
msProjectExperts
"We wrote the books on Project Server"
http://www.msprojectexperts.com
FAQ - http://www.projectserverexperts.com



message
Just one more question fellows. The purpose for using PERT in my
project
is
to provide the ability to crash a certain project to meet some
deadline.
Crashing the project will make use of the PERT durations [optimistic
/
pessimistic ..] to see if the project can make it for the new
deadline.
Taking into account that we have dependencies between tasks in the
project,
manual calculations of the PERT crashed timeline would not be that
easy!!
Any Clues???

:

When I used the PERT toolbar while recording a macro, I didn't
get
any
code.
So I don't know if there is an explicit object to call.

However, you could do the calculations manually. PERT uses the
durations in
Duration1, 2 and 3 for Optimistic, Expected, and Pessimistic. It
then
figures out the start/finish dates for each option and puts them
into
Start1/Finish1, Start2/Finish2, and Start3/Finish3. The task's
duration is
calculated using the default weighting of 1x the Optimistic
Duration,
4x the
Expected duration and 1x the Pessimistic duration. Of course you
could
change the weighting, but in order to keep with Microsoft's PERT
rule,
the
sum of the multipliers must equal 6.

Hope this helps.
--
Ed Morrison
msProjectExperts
"We wrote the books on Project Server"
http://www.msprojectexperts.com
FAQ - http://www.projectserverexperts.com



I'm working on a project that includes project automation. I'm
been
asked
to
include calculations of durations according to optimistic /
pessimistic
ratios using PERT. Does MS Project automation allow for
interaction
with
PERT?