Critical path in MSP

Hi everyone.

I'm relatively new to using MSP in anger and I have a
major issue with the way it shows the critical path.

If all the tasks on the CP are dependencies of each other
then it's all fine and dandy with nice red tasks to
highlight the CP.

If however you assign no dependencies but have all tasks
assigned to the same resource, then it does not show
these as the CP.

Now my understanding of the definition of the CP is any
tasks that, if delayed, will cause a delay in the
earliest completion time of the project. By definition
if all tasks are assigned to a single resource then a
delay in any task will therefore cause a delay in the
project and so is critical!

Anyone got any thoughts on this as it's quite significant
if I can't easily identify the CP in a large schedule
(currently around 700 lines and growing.)

Dave.

John
Sun Sep 05 13:06:59 CDT 2004


Dave,
Just for reference, Project determines the critical path based on Total
Slack (see Tools/Options/Calculation tab). If your "plan" has no
linkages between tasks, my guess is that the Total Slack values are
quite large and therefore nothing is critical. You have a strange plan
however. If there is only one resource how can none of the tasks be
dependent on one another? Granted the single resource can possibly work
on a couple of tasks simultaneously but for the most part, one task has
to be finished before the next can start. Either that or the Duration
for each task has to equal the Duration of the whole plan and then
everything is critical!

With a single resource, it sounds like you need to do resource leveling.
Basically it takes the priority given to each task and allocates the
resource's time to each task based on the priority. Provided there is a
bar style to show critical tasks, with no task linkages and the whole
project leveled, the last task will be the only critical task because it
is the only one with the default "0" days of Total Slack.

My suggestion, if you expect to see a realistic critical path, link the
tasks in a logical sequence of completion. If you contend that none of
the tasks are dependently related remember this, every task in a valid
project plan MUST have a successor. If nothing else, it must be the end
milestone. Otherwise, why are the tasks being done at all?

Hope this helps.
John

anonymous
Sun Sep 05 14:01:26 CDT 2004

John.

The project with a single resource is just an example one
to illustrate my point.

Yes my real project has normal task dependencies and
these are entered as required, but having done all this
there are still cases where what I consider to be the
entire CP is not highlighted.

Further to this if I have to enter non-real dependencies
just to get a CP highlighted then this will firstly take
a lot of time to do in a large project, and secondly be
somewhat going against the reason for using a tool to
help determine when to do certain tasks.

I'll try and give a simple and real example here to show
the point. Say I have 4 tasks, their durations are 3,4,5
& 3 respectively. Tasks 1 & 4 use Resource A and Tasks 2
& 3 use Resource B. Task 2 is a pred. to task 1 and
tasks 1 & 3 are pred. to task 4.

Here all tasks have a successor.

With this MSP shows tasks 3 & 4 as critical but not task
2, however if task 2 slips then the whole project slips.

You'll probably have to enter this in MSP to see it,
shame I can't attach a file here!


Dave.

Jan
Mon Sep 06 02:34:10 CDT 2004

Hi,

I disagree.
I entered your task ans resources in MSP.
First, without resource leveling, tasks 1, 2 and 4 are critical, not task 3.
When you say task 3 is critical, that means you have performed resource
leveling.

But starting from the assumption that you optimize resoruce usage all the
time, your statement that a delay on task 2 causes a delay on the project is
wrong.

When I introduce (via a constraint) for task 2 a delay lower than its total
slack after leveling (say 1 day) and I re-do Resource Leveling to optimize
my resource usage, Task 3 gets split and the PROJECT END DATE DOES NOT MOVE.
Task 2 is not critical in a resoruce-leveled environment.

Of course when task 2 gets delayed AND resoruce B hasn't started work on
task 3, then your project gets delayed.
But which of the 2 assumptions should Project take? It assumes that you are
actively managing, such that you have your resources work a maximum..

Greetings,



--
Jan De Messemaeker
Microsoft Project Most Valuable Professional
http://users.online.be/prom-ade/index.htm
32-495-300 620
<anonymous@discussions.microsoft.com> schreef in bericht
news:66e701c4937a$bebd32a0$a301280a@phx.gbl...
> John.
>
> The project with a single resource is just an example one
> to illustrate my point.
>
> Yes my real project has normal task dependencies and
> these are entered as required, but having done all this
> there are still cases where what I consider to be the
> entire CP is not highlighted.
>
> Further to this if I have to enter non-real dependencies
> just to get a CP highlighted then this will firstly take
> a lot of time to do in a large project, and secondly be
> somewhat going against the reason for using a tool to
> help determine when to do certain tasks.
>
> I'll try and give a simple and real example here to show
> the point. Say I have 4 tasks, their durations are 3,4,5
> & 3 respectively. Tasks 1 & 4 use Resource A and Tasks 2
> & 3 use Resource B. Task 2 is a pred. to task 1 and
> tasks 1 & 3 are pred. to task 4.
>
> Here all tasks have a successor.
>
> With this MSP shows tasks 3 & 4 as critical but not task
> 2, however if task 2 slips then the whole project slips.
>
> You'll probably have to enter this in MSP to see it,
> shame I can't attach a file here!
>
>
> Dave.

Dave
Mon Sep 06 05:27:30 CDT 2004

Hi Jan

I see what you are saying and I don't totally disagree,
but you are making a couple of assumptions, firstly you
are assuming that task 3 can be split, but that's not too
important for this.

However more importantly you are assuming that the delay
in task 2 is just a delay in it's starting time. What
will affect the schedule and what makes this task
critical is that it may take longer to execute than
estimated. Tasks 2, 3 & 4 are all critical in that their
total time to complete must not go beyond the estimate.
Task 1 can take longer to complete (upto 2 days longer)
and the schedule is not affected.

Dave.

>-----Original Message-----
>Hi,
>
>I disagree.
>I entered your task ans resources in MSP.
>First, without resource leveling, tasks 1, 2 and 4 are
critical, not task 3.
>When you say task 3 is critical, that means you have
performed resource
>leveling.
>
>But starting from the assumption that you optimize
resoruce usage all the
>time, your statement that a delay on task 2 causes a
delay on the project is
>wrong.
>
>When I introduce (via a constraint) for task 2 a delay
lower than its total
>slack after leveling (say 1 day) and I re-do Resource
Leveling to optimize
>my resource usage, Task 3 gets split and the PROJECT END
DATE DOES NOT MOVE.
>Task 2 is not critical in a resoruce-leveled environment.
>
>Of course when task 2 gets delayed AND resoruce B hasn't
started work on
>task 3, then your project gets delayed.
>But which of the 2 assumptions should Project take? It
assumes that you are
>actively managing, such that you have your resources
work a maximum..
>
>Greetings,
>
>
>
>--
>Jan De Messemaeker
>Microsoft Project Most Valuable Professional
>http://users.online.be/prom-ade/index.htm
>32-495-300 620
><anonymous@discussions.microsoft.com> schreef in bericht
>news:66e701c4937a$bebd32a0$a301280a@phx.gbl...
>> John.
>>
>> The project with a single resource is just an example
one
>> to illustrate my point.
>>
>> Yes my real project has normal task dependencies and
>> these are entered as required, but having done all this
>> there are still cases where what I consider to be the
>> entire CP is not highlighted.
>>
>> Further to this if I have to enter non-real
dependencies
>> just to get a CP highlighted then this will firstly
take
>> a lot of time to do in a large project, and secondly be
>> somewhat going against the reason for using a tool to
>> help determine when to do certain tasks.
>>
>> I'll try and give a simple and real example here to
show
>> the point. Say I have 4 tasks, their durations are
3,4,5
>> & 3 respectively. Tasks 1 & 4 use Resource A and
Tasks 2
>> & 3 use Resource B. Task 2 is a pred. to task 1 and
>> tasks 1 & 3 are pred. to task 4.
>>
>> Here all tasks have a successor.
>>
>> With this MSP shows tasks 3 & 4 as critical but not
task
>> 2, however if task 2 slips then the whole project
slips.
>>
>> You'll probably have to enter this in MSP to see it,
>> shame I can't attach a file here!
>>
>>
>> Dave.
>
>
>.
>

Steve
Mon Sep 06 07:31:25 CDT 2004

You are describing what is known as the "Resource Critical Path" which is
distinct from the Critical Path as defined in CPM. The "vanilla" critical
path is defined in terms of the process logic only and that is what MS
Project, and I think all other scheduling software, uses. It ignores
resource dependencies unless you model them through the use of predecessor /
successor linking (IMHO not a good idea). The resource critical path takes
into account both process logic and resource competition among tasks.
Determining the resource critical path and monitoring performance against it
is a manual process and I'm not aware of any scheduling software that has
the capability of calculating it for you. If you think about it, it makes a
certain sense to handle it that way because in your example, MSP has no way
of knowing but what you might have a resource C waiting in the wings whom
you could substitute for B on task 3 if B is still tied up finishing a
delayed finishing task 2 when 3 is due to start, thus preserving 3's
original post-leveling start and consequently the post-leveled critical path
of S->3->4->F.

http://www.allpm.com/article.php?sid=1083

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


"Dave N" <anonymous@discussions.microsoft.com> wrote in message
news:69ee01c493fc$1d81e430$a501280a@phx.gbl...
> Hi Jan
>
> I see what you are saying and I don't totally disagree,
> but you are making a couple of assumptions, firstly you
> are assuming that task 3 can be split, but that's not too
> important for this.
>
> However more importantly you are assuming that the delay
> in task 2 is just a delay in it's starting time. What
> will affect the schedule and what makes this task
> critical is that it may take longer to execute than
> estimated. Tasks 2, 3 & 4 are all critical in that their
> total time to complete must not go beyond the estimate.
> Task 1 can take longer to complete (upto 2 days longer)
> and the schedule is not affected.
>
> Dave.
>
> >-----Original Message-----
> >Hi,
> >
> >I disagree.
> >I entered your task ans resources in MSP.
> >First, without resource leveling, tasks 1, 2 and 4 are
> critical, not task 3.
> >When you say task 3 is critical, that means you have
> performed resource
> >leveling.
> >
> >But starting from the assumption that you optimize
> resoruce usage all the
> >time, your statement that a delay on task 2 causes a
> delay on the project is
> >wrong.
> >
> >When I introduce (via a constraint) for task 2 a delay
> lower than its total
> >slack after leveling (say 1 day) and I re-do Resource
> Leveling to optimize
> >my resource usage, Task 3 gets split and the PROJECT END
> DATE DOES NOT MOVE.
> >Task 2 is not critical in a resoruce-leveled environment.
> >
> >Of course when task 2 gets delayed AND resoruce B hasn't
> started work on
> >task 3, then your project gets delayed.
> >But which of the 2 assumptions should Project take? It
> assumes that you are
> >actively managing, such that you have your resources
> work a maximum..
> >
> >Greetings,
> >
> >
> >
> >--
> >Jan De Messemaeker
> >Microsoft Project Most Valuable Professional
> >http://users.online.be/prom-ade/index.htm
> >32-495-300 620
> ><anonymous@discussions.microsoft.com> schreef in bericht
> >news:66e701c4937a$bebd32a0$a301280a@phx.gbl...
> >> John.
> >>
> >> The project with a single resource is just an example
> one
> >> to illustrate my point.
> >>
> >> Yes my real project has normal task dependencies and
> >> these are entered as required, but having done all this
> >> there are still cases where what I consider to be the
> >> entire CP is not highlighted.
> >>
> >> Further to this if I have to enter non-real
> dependencies
> >> just to get a CP highlighted then this will firstly
> take
> >> a lot of time to do in a large project, and secondly be
> >> somewhat going against the reason for using a tool to
> >> help determine when to do certain tasks.
> >>
> >> I'll try and give a simple and real example here to
> show
> >> the point. Say I have 4 tasks, their durations are
> 3,4,5
> >> & 3 respectively. Tasks 1 & 4 use Resource A and
> Tasks 2
> >> & 3 use Resource B. Task 2 is a pred. to task 1 and
> >> tasks 1 & 3 are pred. to task 4.
> >>
> >> Here all tasks have a successor.
> >>
> >> With this MSP shows tasks 3 & 4 as critical but not
> task
> >> 2, however if task 2 slips then the whole project
> slips.
> >>
> >> You'll probably have to enter this in MSP to see it,
> >> shame I can't attach a file here!
> >>
> >>
> >> Dave.
> >
> >
> >.
> >

Mark
Mon Sep 06 08:21:33 CDT 2004

What you are looking for is the "Critical chain" a fancy name for the
"resource leveled critical path"

Search the web for "Critical chain" and you'll find more than you wanted to
know...

Mark


--
_________________________________________________________
Mark Durrenberger, PMP
Principal, Oak Associates, Inc, www.oakinc.com
"Advancing the Theory and Practice of Project Management"
________________________________________________________

The nicest thing about NOT planning is that failure
comes as a complete surprise and is not preceded by
a period of worry and depression.

- Sir John Harvey-Jones
"Dave N" <anonymous@discussions.microsoft.com> wrote in message
news:665e01c49366$55c2bef0$a301280a@phx.gbl...
> Hi everyone.
>
> I'm relatively new to using MSP in anger and I have a
> major issue with the way it shows the critical path.
>
> If all the tasks on the CP are dependencies of each other
> then it's all fine and dandy with nice red tasks to
> highlight the CP.
>
> If however you assign no dependencies but have all tasks
> assigned to the same resource, then it does not show
> these as the CP.
>
> Now my understanding of the definition of the CP is any
> tasks that, if delayed, will cause a delay in the
> earliest completion time of the project. By definition
> if all tasks are assigned to a single resource then a
> delay in any task will therefore cause a delay in the
> project and so is critical!
>
> Anyone got any thoughts on this as it's quite significant
> if I can't easily identify the CP in a large schedule
> (currently around 700 lines and growing.)
>
> Dave.

Dave
Mon Sep 06 10:40:30 CDT 2004

Steve.

Thanks for that, I think you confirmed my original
concerns that neither MSP or any other planning apps.
take account of the resources in CPA. They use the
calculation of slack to determine the CP and this is how
you would do it if using pen and paper and AonA or AonN
analysis.

At least now I know for sure!

Cheers.

Dave.


>-----Original Message-----
>You are describing what is known as the "Resource
Critical Path" which is
>distinct from the Critical Path as defined in CPM.
The "vanilla" critical
>path is defined in terms of the process logic only and
that is what MS
>Project, and I think all other scheduling software,
uses. It ignores
>resource dependencies unless you model them through the
use of predecessor /
>successor linking (IMHO not a good idea). The resource
critical path takes
>into account both process logic and resource competition
among tasks.
>Determining the resource critical path and monitoring
performance against it
>is a manual process and I'm not aware of any scheduling
software that has
>the capability of calculating it for you. If you think
about it, it makes a
>certain sense to handle it that way because in your
example, MSP has no way
>of knowing but what you might have a resource C waiting
in the wings whom
>you could substitute for B on task 3 if B is still tied
up finishing a
>delayed finishing task 2 when 3 is due to start, thus
preserving 3's
>original post-leveling start and consequently the post-
leveled critical path
>of S->3->4->F.
>
>http://www.allpm.com/article.php?sid=1083
>
>--
>Steve House [MVP]
>MS Project Trainer/Consultant
>Visit http://www.mvps.org/project/faqs.htm for the FAQs
>
>
>"Dave N" <anonymous@discussions.microsoft.com> wrote in
message
>news:69ee01c493fc$1d81e430$a501280a@phx.gbl...
>> Hi Jan
>>
>> I see what you are saying and I don't totally disagree,
>> but you are making a couple of assumptions, firstly you
>> are assuming that task 3 can be split, but that's not
too
>> important for this.
>>
>> However more importantly you are assuming that the
delay
>> in task 2 is just a delay in it's starting time. What
>> will affect the schedule and what makes this task
>> critical is that it may take longer to execute than
>> estimated. Tasks 2, 3 & 4 are all critical in that
their
>> total time to complete must not go beyond the estimate.
>> Task 1 can take longer to complete (upto 2 days longer)
>> and the schedule is not affected.
>>
>> Dave.
>>
>> >-----Original Message-----
>> >Hi,
>> >
>> >I disagree.
>> >I entered your task ans resources in MSP.
>> >First, without resource leveling, tasks 1, 2 and 4 are
>> critical, not task 3.
>> >When you say task 3 is critical, that means you have
>> performed resource
>> >leveling.
>> >
>> >But starting from the assumption that you optimize
>> resoruce usage all the
>> >time, your statement that a delay on task 2 causes a
>> delay on the project is
>> >wrong.
>> >
>> >When I introduce (via a constraint) for task 2 a delay
>> lower than its total
>> >slack after leveling (say 1 day) and I re-do Resource
>> Leveling to optimize
>> >my resource usage, Task 3 gets split and the PROJECT
END
>> DATE DOES NOT MOVE.
>> >Task 2 is not critical in a resoruce-leveled
environment.
>> >
>> >Of course when task 2 gets delayed AND resoruce B
hasn't
>> started work on
>> >task 3, then your project gets delayed.
>> >But which of the 2 assumptions should Project take? It
>> assumes that you are
>> >actively managing, such that you have your resources
>> work a maximum..
>> >
>> >Greetings,
>> >
>> >
>> >
>> >--
>> >Jan De Messemaeker
>> >Microsoft Project Most Valuable Professional
>> >http://users.online.be/prom-ade/index.htm
>> >32-495-300 620
>> ><anonymous@discussions.microsoft.com> schreef in
bericht
>> >news:66e701c4937a$bebd32a0$a301280a@phx.gbl...
>> >> John.
>> >>
>> >> The project with a single resource is just an
example
>> one
>> >> to illustrate my point.
>> >>
>> >> Yes my real project has normal task dependencies and
>> >> these are entered as required, but having done all
this
>> >> there are still cases where what I consider to be
the
>> >> entire CP is not highlighted.
>> >>
>> >> Further to this if I have to enter non-real
>> dependencies
>> >> just to get a CP highlighted then this will firstly
>> take
>> >> a lot of time to do in a large project, and
secondly be
>> >> somewhat going against the reason for using a tool
to
>> >> help determine when to do certain tasks.
>> >>
>> >> I'll try and give a simple and real example here to
>> show
>> >> the point. Say I have 4 tasks, their durations are
>> 3,4,5
>> >> & 3 respectively. Tasks 1 & 4 use Resource A and
>> Tasks 2
>> >> & 3 use Resource B. Task 2 is a pred. to task 1 and
>> >> tasks 1 & 3 are pred. to task 4.
>> >>
>> >> Here all tasks have a successor.
>> >>
>> >> With this MSP shows tasks 3 & 4 as critical but not
>> task
>> >> 2, however if task 2 slips then the whole project
>> slips.
>> >>
>> >> You'll probably have to enter this in MSP to see it,
>> >> shame I can't attach a file here!
>> >>
>> >>
>> >> Dave.
>> >
>> >
>> >.
>> >
>
>
>.
>

davegb
Mon Sep 06 10:49:04 CDT 2004

If a task can have a 2 day delay in it's start, and therefore, it's
finish, without extending the project end date, it can also have a 2
day extension to it's duration. If it has 2 days or more of Total
Slack, neither condition effects the critical path.
There are actually 3 definitions of CP, each superceding the previous,
when done in the logical order of a CP analysis. The first is the
longest path, the second is the path along which Early Start = Late
Start, and the 3rd is the path with 0 Total Slack. Since Total Slack =
Late Start - Early Start, these are the same paths. Since the along
the longest path, Late Start will always equal Early Start, the three
are the same.
The second biggest problem people have in using Project is not
understanding these relationships and the fact that they need Schedule
Continuity to make it all work.
Hope this helps.

David G. Bellamy
Bellamy Consulting

"Dave N" <anonymous@discussions.microsoft.com> wrote in message news:<69ee01c493fc$1d81e430$a501280a@phx.gbl>...
> Hi Jan
>
> I see what you are saying and I don't totally disagree,
> but you are making a couple of assumptions, firstly you
> are assuming that task 3 can be split, but that's not too
> important for this.
>
> However more importantly you are assuming that the delay
> in task 2 is just a delay in it's starting time. What
> will affect the schedule and what makes this task
> critical is that it may take longer to execute than
> estimated. Tasks 2, 3 & 4 are all critical in that their
> total time to complete must not go beyond the estimate.
> Task 1 can take longer to complete (upto 2 days longer)
> and the schedule is not affected.
>
> Dave.
>
> >-----Original Message-----
> >Hi,
> >
> >I disagree.
> >I entered your task ans resources in MSP.
> >First, without resource leveling, tasks 1, 2 and 4 are
> critical, not task 3.
> >When you say task 3 is critical, that means you have
> performed resource
> >leveling.
> >
> >But starting from the assumption that you optimize
> resoruce usage all the
> >time, your statement that a delay on task 2 causes a
> delay on the project is
> >wrong.
> >
> >When I introduce (via a constraint) for task 2 a delay
> lower than its total
> >slack after leveling (say 1 day) and I re-do Resource
> Leveling to optimize
> >my resource usage, Task 3 gets split and the PROJECT END
> DATE DOES NOT MOVE.
> >Task 2 is not critical in a resoruce-leveled environment.
> >
> >Of course when task 2 gets delayed AND resoruce B hasn't
> started work on
> >task 3, then your project gets delayed.
> >But which of the 2 assumptions should Project take? It
> assumes that you are
> >actively managing, such that you have your resources
> work a maximum..
> >
> >Greetings,
> >
> >
> >
> >--
> >Jan De Messemaeker
> >Microsoft Project Most Valuable Professional
> >http://users.online.be/prom-ade/index.htm
> >32-495-300 620
> ><anonymous@discussions.microsoft.com> schreef in bericht
> >news:66e701c4937a$bebd32a0$a301280a@phx.gbl...
> >> John.
> >>
> >> The project with a single resource is just an example
> one
> >> to illustrate my point.
> >>
> >> Yes my real project has normal task dependencies and
> >> these are entered as required, but having done all this
> >> there are still cases where what I consider to be the
> >> entire CP is not highlighted.
> >>
> >> Further to this if I have to enter non-real
> dependencies
> >> just to get a CP highlighted then this will firstly
> take
> >> a lot of time to do in a large project, and secondly be
> >> somewhat going against the reason for using a tool to
> >> help determine when to do certain tasks.
> >>
> >> I'll try and give a simple and real example here to
> show
> >> the point. Say I have 4 tasks, their durations are
> 3,4,5
> >> & 3 respectively. Tasks 1 & 4 use Resource A and
> Tasks 2
> >> & 3 use Resource B. Task 2 is a pred. to task 1 and
> >> tasks 1 & 3 are pred. to task 4.
> >>
> >> Here all tasks have a successor.
> >>
> >> With this MSP shows tasks 3 & 4 as critical but not
> task
> >> 2, however if task 2 slips then the whole project
> slips.
> >>
> >> You'll probably have to enter this in MSP to see it,
> >> shame I can't attach a file here!
> >>
> >>
> >> Dave.
> >
> >
> >.
> >

Dave
Mon Sep 06 11:02:22 CDT 2004

Mark.

Yep, looks like you're right, so looks like it's off to
Amazon to buy a book on critical chain! :-)

Thanks.

Dave.


>-----Original Message-----
>What you are looking for is the "Critical chain" a fancy
name for the
>"resource leveled critical path"
>
>Search the web for "Critical chain" and you'll find more
than you wanted to
>know...
>
>Mark
>
>
>--
>_________________________________________________________
>Mark Durrenberger, PMP
>Principal, Oak Associates, Inc, www.oakinc.com
>"Advancing the Theory and Practice of Project Management"
>________________________________________________________
>
>The nicest thing about NOT planning is that failure
>comes as a complete surprise and is not preceded by
>a period of worry and depression.
>
>- Sir John Harvey-Jones
>"Dave N" <anonymous@discussions.microsoft.com> wrote in
message
>news:665e01c49366$55c2bef0$a301280a@phx.gbl...
>> Hi everyone.
>>
>> I'm relatively new to using MSP in anger and I have a
>> major issue with the way it shows the critical path.
>>
>> If all the tasks on the CP are dependencies of each
other
>> then it's all fine and dandy with nice red tasks to
>> highlight the CP.
>>
>> If however you assign no dependencies but have all
tasks
>> assigned to the same resource, then it does not show
>> these as the CP.
>>
>> Now my understanding of the definition of the CP is any
>> tasks that, if delayed, will cause a delay in the
>> earliest completion time of the project. By definition
>> if all tasks are assigned to a single resource then a
>> delay in any task will therefore cause a delay in the
>> project and so is critical!
>>
>> Anyone got any thoughts on this as it's quite
significant
>> if I can't easily identify the CP in a large schedule
>> (currently around 700 lines and growing.)
>>
>> Dave.
>
>
>.
>

Steve
Mon Sep 06 11:11:25 CDT 2004

Yep - MSP is based on classical CPM with Action-on-Node.
--
Steve House [MVP]
MS Project Trainer/Consultant
Visit http://www.mvps.org/project/faqs.htm for the FAQs


"Dave N" <anonymous@discussions.microsoft.com> wrote in message
news:6ced01c49427$d706f7d0$a501280a@phx.gbl...
> Steve.
>
> Thanks for that, I think you confirmed my original
> concerns that neither MSP or any other planning apps.
> take account of the resources in CPA. They use the
> calculation of slack to determine the CP and this is how
> you would do it if using pen and paper and AonA or AonN
> analysis.
>
> At least now I know for sure!
>
> Cheers.
>
> Dave.
>
>
> >-----Original Message-----
> >You are describing what is known as the "Resource
> Critical Path" which is
> >distinct from the Critical Path as defined in CPM.
> The "vanilla" critical
> >path is defined in terms of the process logic only and
> that is what MS
> >Project, and I think all other scheduling software,
> uses. It ignores
> >resource dependencies unless you model them through the
> use of predecessor /
> >successor linking (IMHO not a good idea). The resource
> critical path takes
> >into account both process logic and resource competition
> among tasks.
> >Determining the resource critical path and monitoring
> performance against it
> >is a manual process and I'm not aware of any scheduling
> software that has
> >the capability of calculating it for you. If you think
> about it, it makes a
> >certain sense to handle it that way because in your
> example, MSP has no way
> >of knowing but what you might have a resource C waiting
> in the wings whom
> >you could substitute for B on task 3 if B is still tied
> up finishing a
> >delayed finishing task 2 when 3 is due to start, thus
> preserving 3's
> >original post-leveling start and consequently the post-
> leveled critical path
> >of S->3->4->F.
> >
> >http://www.allpm.com/article.php?sid=1083
> >
> >--
> >Steve House [MVP]
> >MS Project Trainer/Consultant
> >Visit http://www.mvps.org/project/faqs.htm for the FAQs
> >
> >
> >"Dave N" <anonymous@discussions.microsoft.com> wrote in
> message
> >news:69ee01c493fc$1d81e430$a501280a@phx.gbl...
> >> Hi Jan
> >>
> >> I see what you are saying and I don't totally disagree,
> >> but you are making a couple of assumptions, firstly you
> >> are assuming that task 3 can be split, but that's not
> too
> >> important for this.
> >>
> >> However more importantly you are assuming that the
> delay
> >> in task 2 is just a delay in it's starting time. What
> >> will affect the schedule and what makes this task
> >> critical is that it may take longer to execute than
> >> estimated. Tasks 2, 3 & 4 are all critical in that
> their
> >> total time to complete must not go beyond the estimate.
> >> Task 1 can take longer to complete (upto 2 days longer)
> >> and the schedule is not affected.
> >>
> >> Dave.
> >>
> >> >-----Original Message-----
> >> >Hi,
> >> >
> >> >I disagree.
> >> >I entered your task ans resources in MSP.
> >> >First, without resource leveling, tasks 1, 2 and 4 are
> >> critical, not task 3.
> >> >When you say task 3 is critical, that means you have
> >> performed resource
> >> >leveling.
> >> >
> >> >But starting from the assumption that you optimize
> >> resoruce usage all the
> >> >time, your statement that a delay on task 2 causes a
> >> delay on the project is
> >> >wrong.
> >> >
> >> >When I introduce (via a constraint) for task 2 a delay
> >> lower than its total
> >> >slack after leveling (say 1 day) and I re-do Resource
> >> Leveling to optimize
> >> >my resource usage, Task 3 gets split and the PROJECT
> END
> >> DATE DOES NOT MOVE.
> >> >Task 2 is not critical in a resoruce-leveled
> environment.
> >> >
> >> >Of course when task 2 gets delayed AND resoruce B
> hasn't
> >> started work on
> >> >task 3, then your project gets delayed.
> >> >But which of the 2 assumptions should Project take? It
> >> assumes that you are
> >> >actively managing, such that you have your resources
> >> work a maximum..
> >> >
> >> >Greetings,
> >> >
> >> >
> >> >
> >> >--
> >> >Jan De Messemaeker
> >> >Microsoft Project Most Valuable Professional
> >> >http://users.online.be/prom-ade/index.htm
> >> >32-495-300 620
> >> ><anonymous@discussions.microsoft.com> schreef in
> bericht
> >> >news:66e701c4937a$bebd32a0$a301280a@phx.gbl...
> >> >> John.
> >> >>
> >> >> The project with a single resource is just an
> example
> >> one
> >> >> to illustrate my point.
> >> >>
> >> >> Yes my real project has normal task dependencies and
> >> >> these are entered as required, but having done all
> this
> >> >> there are still cases where what I consider to be
> the
> >> >> entire CP is not highlighted.
> >> >>
> >> >> Further to this if I have to enter non-real
> >> dependencies
> >> >> just to get a CP highlighted then this will firstly
> >> take
> >> >> a lot of time to do in a large project, and
> secondly be
> >> >> somewhat going against the reason for using a tool
> to
> >> >> help determine when to do certain tasks.
> >> >>
> >> >> I'll try and give a simple and real example here to
> >> show
> >> >> the point. Say I have 4 tasks, their durations are
> >> 3,4,5
> >> >> & 3 respectively. Tasks 1 & 4 use Resource A and
> >> Tasks 2
> >> >> & 3 use Resource B. Task 2 is a pred. to task 1 and
> >> >> tasks 1 & 3 are pred. to task 4.
> >> >>
> >> >> Here all tasks have a successor.
> >> >>
> >> >> With this MSP shows tasks 3 & 4 as critical but not
> >> task
> >> >> 2, however if task 2 slips then the whole project
> >> slips.
> >> >>
> >> >> You'll probably have to enter this in MSP to see it,
> >> >> shame I can't attach a file here!
> >> >>
> >> >>
> >> >> Dave.
> >> >
> >> >
> >> >.
> >> >
> >
> >
> >.
> >

Mark
Mon Sep 06 12:09:54 CDT 2004

Do not buy "Critical Chain" by Goldratt - it is a thinly veiled attempt to
sell consulting services - gives you just enough info to want to call him
and ask more questions...

I wish I could remember the author to recommend... Sorry.
Mark

ps before buying any books - see what is free on the web

fwiw - a lot of Critical chain PM is general good PM practices - many of the
CC people will claim that no one ever thought of it before but their
memories are either short or selective for marketing purposes...:-)



--
_________________________________________________________
Mark Durrenberger, PMP
Principal, Oak Associates, Inc, www.oakinc.com
"Advancing the Theory and Practice of Project Management"
________________________________________________________

The nicest thing about NOT planning is that failure
comes as a complete surprise and is not preceded by
a period of worry and depression.

- Sir John Harvey-Jones
"Dave N" <anonymous@discussions.microsoft.com> wrote in message
news:6c3801c4942a$e5090f50$a601280a@phx.gbl...
> Mark.
>
> Yep, looks like you're right, so looks like it's off to
> Amazon to buy a book on critical chain! :-)
>
> Thanks.
>
> Dave.
>
>
> >-----Original Message-----
> >What you are looking for is the "Critical chain" a fancy
> name for the
> >"resource leveled critical path"
> >
> >Search the web for "Critical chain" and you'll find more
> than you wanted to
> >know...
> >
> >Mark
> >
> >
> >--
> >_________________________________________________________
> >Mark Durrenberger, PMP
> >Principal, Oak Associates, Inc, www.oakinc.com
> >"Advancing the Theory and Practice of Project Management"
> >________________________________________________________
> >
> >The nicest thing about NOT planning is that failure
> >comes as a complete surprise and is not preceded by
> >a period of worry and depression.
> >
> >- Sir John Harvey-Jones
> >"Dave N" <anonymous@discussions.microsoft.com> wrote in
> message
> >news:665e01c49366$55c2bef0$a301280a@phx.gbl...
> >> Hi everyone.
> >>
> >> I'm relatively new to using MSP in anger and I have a
> >> major issue with the way it shows the critical path.
> >>
> >> If all the tasks on the CP are dependencies of each
> other
> >> then it's all fine and dandy with nice red tasks to
> >> highlight the CP.
> >>
> >> If however you assign no dependencies but have all
> tasks
> >> assigned to the same resource, then it does not show
> >> these as the CP.
> >>
> >> Now my understanding of the definition of the CP is any
> >> tasks that, if delayed, will cause a delay in the
> >> earliest completion time of the project. By definition
> >> if all tasks are assigned to a single resource then a
> >> delay in any task will therefore cause a delay in the
> >> project and so is critical!
> >>
> >> Anyone got any thoughts on this as it's quite
> significant
> >> if I can't easily identify the CP in a large schedule
> >> (currently around 700 lines and growing.)
> >>
> >> Dave.
> >
> >
> >.
> >

JackD
Tue Sep 07 11:41:23 CDT 2004


"Mark Durrenberger" <durrenm@yahoo.com> wrote in message
news:%23RJEcRDlEHA.3432@TK2MSFTNGP14.phx.gbl...
> Do not buy "Critical Chain" by Goldratt - it is a thinly veiled attempt to
> sell consulting services - gives you just enough info to want to call him
> and ask more questions...
>
> I wish I could remember the author to recommend... Sorry.
> Mark
>
> ps before buying any books - see what is free on the web
>
> fwiw - a lot of Critical chain PM is general good PM practices - many of
the
> CC people will claim that no one ever thought of it before but their
> memories are either short or selective for marketing purposes...:-)

How are you going to sell the same old stuff unless you give it a new name?

-Jack "New and Improved"

ScottButton
Wed Oct 06 11:55:07 CDT 2004

I recommend the book "Critical Chain Project Management" by Lawrence P.
Leach. Also, a couple of good websites:
http://www.pdinstitute.com/

http://www.focusedperformance.com/


"Mark Durrenberger" wrote:

> What you are looking for is the "Critical chain" a fancy name for the
> "resource leveled critical path"
>
> Search the web for "Critical chain" and you'll find more than you wanted to
> know...
>
> Mark
>
>
> --
> _________________________________________________________
> Mark Durrenberger, PMP
> Principal, Oak Associates, Inc, www.oakinc.com
> "Advancing the Theory and Practice of Project Management"
> ________________________________________________________
>
> The nicest thing about NOT planning is that failure
> comes as a complete surprise and is not preceded by
> a period of worry and depression.
>
> - Sir John Harvey-Jones
> "Dave N" <anonymous@discussions.microsoft.com> wrote in message
> news:665e01c49366$55c2bef0$a301280a@phx.gbl...
> > Hi everyone.
> >
> > I'm relatively new to using MSP in anger and I have a
> > major issue with the way it shows the critical path.
> >
> > If all the tasks on the CP are dependencies of each other
> > then it's all fine and dandy with nice red tasks to
> > highlight the CP.
> >
> > If however you assign no dependencies but have all tasks
> > assigned to the same resource, then it does not show
> > these as the CP.
> >
> > Now my understanding of the definition of the CP is any
> > tasks that, if delayed, will cause a delay in the
> > earliest completion time of the project. By definition
> > if all tasks are assigned to a single resource then a
> > delay in any task will therefore cause a delay in the
> > project and so is critical!
> >
> > Anyone got any thoughts on this as it's quite significant
> > if I can't easily identify the CP in a large schedule
> > (currently around 700 lines and growing.)
> >
> > Dave.
>
>
>