TOPIC: Is A Project Ahead Of Schedule When It Has An SPI

I am working through sample questions in anticipation of taking the PMP exam on June 2.

In question 25050, the scenario is given as the project has an SPI of 1.02 and the PM reports that the project is on schedule. Among the choices for answering are, that the PM is correct, the PM is not correct, the project is ahead of schedule, etc. The answer I chose was that the project is ahead of schedule. The given correct answer is that the project is on schedule with an explanation that 1.02 really isn't that much ahead of schedule. The PMBOK guide is quite clear that 1.0 is on schedule, < 1.0 behind and > 1.0 ahead. There is no guidance for any tolerance or similar variance. Therefore, unless the question provides information that within the schedule management plan and SPI within a certain tolerance , e.g. .97 - 1.03, will be considered on schedule, how would I be able to determine if 1.03, 1.04 or 1.05 is on or ahead of schedule?

Hi John,

regarding the PMBOK fifth edition on page 89 you will find a general description regarding Schedule Forcasts:

The schedule forcasts are derived from progess against the schedule baseline and
computed time estimate to complete (ETC).
This is typically expressed in terms of schedule variance (SV) and schedule performance index (SPI)

On page 149 in the PMBOK it is described that:
Schedule performance measurements such as schedule variance (SV) and schedule perfomance index (SPI)
used to assess the magnitute of variation to the original schedule basline.

So I already here it is described that you compare project progress against the basline. (your original plan)
and the result should be from a logical point of view:
Behind of what you have planned
Exactly of what you have planned
Ahead of what you have planned

Earned Value Management is just putting this into a formular.
On page 219 in the PMBOK it is described that:
SPI= EV/PV

So if Earned Value is greater than what you have planned (PV) it is positiv and the other way around negativ.
The PMBOK decribes:
An SPI value less than 1.0 indicates less work was completed than was planned.
An SPI greater than 1.0 indicates that more work was completed than was planned.

OK that was a long way to come to your question but now I come to the point
Interesting is that the PMBOK describes the place after the decimal point with one number --> 1.0
and not 1.00.
So from my point of view you need to round the SPI from 1.02 to 1.0 and the PM is correct the project is on schedule!

I think this question is really tricky and I would not worry too much about these kind of questions.
In my PMP exam the questions came across really clear and there was no room for interpretation.

I hope you are happy with the answer

Cheers
Sven

Hi Sven,
hi John,

from my sight of view this question/answer is not tricky, it is just wrong!

The PMBOK Guide says (more often than once i think) clear that the project is on schedulae as far as the SPI is exactly 1.0.
Otherwise the project is either behind or ahead schedule.

Also in the "Practice Standard for Earned Value Management". There are several examples of an SPI mentioned with 2 or even 3 Numbers after the dot!
And i found no place where was talked about rounding the SPI up or down.
And like i said, doing so would just be wrong.
1.02 looks like a very little variance but depending on the basic data it could be a relatvly long time.
So imho an SPI of 1.02 says the project was (may be slightly) ahead ... but ahead.

Just my 2 Cents ...

Markus,

I really appreciate your answer as this is exactly what a good forum needs. Valuable discussions.

And I agree on what you wrote but after all a small question mark is still in my mind

The PMBOK describes on page 224:

An SPI of 1.0 means that the project is exactly on schedule, that the work
actually done so far is exactly the same as the work planned to be
done so far. Other values show the percentage of how much costs are
over or under the budgeted amount for work planned.

Greater than 1.0 = Ahead of schedule
Exactly 1.0 = On schedule
Less than 1.0 = Behind schedule

Here we are all absolutly on the same page: Exactly 1.0 = On schedule

But why do they print 1.0 instead of 1.000000 in the PMBOK ?
(because out of this I came to the conclusion that it must be rounding)
Why do they not just print 1?

There must be a reason behind that and I am really curious to find out what PMI's opinon is.
Maybe I am too curious but I have send PMI a mail and just asked them.
I keep you posted!!

Cheers
Sven

Hi Guys,

Thanks for the lively discussion. To me, the question of what is or isn't significant enough to qualify a project as ahead of schedule becomes something for the PMO or governance functions within a given organization.

As I read it, the PMBOK guidance basically says that when what you have earned is what you planned to have earned (EV/PV) then you are on schedule. The question of how many places to the right of the decimal and discussions into the minutia around it are the fodder which give lawyers a bad reputation.

To me, the bigger, underlying, question is this. I am studying for the PMP exam. The lesson(s) talking about earned value and how to understand the values say to be on schedule the SPI must equal one. In the PM Formulas, which I received from OSP, the description of the values is based on =1, >1 and <1. So what I am really getting at is not so much how an individual organization might interpret 1.000002 as an SPI, but more so for purposes of the exam, that value should be considered as ahead of schedule.

Best regards,

John

John,

you have enough knowledge to answer all EVM related questions on the exam.
As I already wrote above : In my PMP exam the questions came across really clear and there was no room for interpretation.
However if PMI will give me an answer regarding my mail I will post it here.
For now just trust on your knowledge it is really good enough.

Good luck!!

Cheers
Sven

Thanks Sven, I take the exam in a week!

John Feist wrote: Thanks Sven, I take the exam in a week!

Good Luck!

Seems that you are well prepared ...

Sven Gruendahl wrote:
...

But why do they print 1.0 instead of 1.000000 in the PMBOK ?
(because out of this I came to the conclusion that it must be rounding)
Why do they not just print 1?

There must be a reason behind that and I am really curious to find out what PMI's opinon is.
Maybe I am too curious but I have send PMI a mail and just asked them.
I keep you posted!!

Cheers
Sven

Hi Sven,

if i have to guess, why they didn't print just "1" in the PMBOK Guide ...hmmm, my choice would be, because the SPI also could be under "1" or "1.0" ... just like ..."0.96" .... see it?!

Regarding the "rounding theory" (that was my point, John) ... hmmm, let's just look at the example above, a SPI of "0.96".
Following the rounding theory we have to round up the SPI in this case up to "1", right?

Well, this would really not be right, right?

I am exited to read what PMI has to say about it.

Best regards,

Markus

Hi John -

Excellent post! As a PMP Exam Prep Trainer by trade and also a creator of questions for the OSP International PM Exam Simulator, I can offer you the following interpretation and also what I tell my PMP Exam Prep students in my live classes.

If the SPI is "greater than" 1.0, your project is "ahead of schedule"

If the SPI is "less than" 1.0, your project is behind schedule

I the SPI is "exactly" 1.0, your project is "exactly on schedule"

In my project experience if your SPI is “exactly” 1.0 then you are lying!!! (Seriously though, how often is your project "exactly on schedule"?)

And just so you know, this question was intentionally very tricky so that you understand the concepts of the SPI and what the different calculated results mean on your actual projects.

If you stick to the interpretations of the SPI calculated results outlined above when answering exam questions and on your actual real-life projects, you will understand specifically how to interpret and accurately report these results to your project stakeholders.

Thanks for a great question and entertaining forum topic!

Kevin

Kevin W. Reilly, PMP, PMI-ACP
Customer Support
OSP International LLC
Facebook PrepCast: www.facebook.com/PrepCast

Sven Gruendahl wrote: Markus,
....

There must be a reason behind that and I am really curious to find out what PMI's opinon is.
Maybe I am too curious but I have send PMI a mail and just asked them.
I keep you posted!!

Cheers
Sven

Anything new yet?

btw: since every post maid herein has first to be moderated bevor publishing it, i think i am missing 2,3 posts i have made the last few days?!?
but may be, since i am active on a lot of websites/boards, that is just a wrong feeling by my owne ... ^^

Nothing new yet. As I wrote already above I will post an answer from PMI if I get one.
I wrote to customercare and do not have other contact persons. So I gues this will take some weeks due to the priority....

Hi Guys,

Thanks for all the responses. My concern is more about getting some of us students perplexed as I recognize that hitting an exact 1.0 on CPI or SPI is almost impossible without some kind of confidence interval. Unfortunately, there are several other questions out there (and I was too lazy to write down the numbers) where they provide similar scenarios (e.g. an index that is less than .05 +- from 1.0) where the correct answer is that the project is not on budget/schedule.

I'm curious to see what PMI has to say.

:{)

Here is the answer from PMI. I posted it as a seperate topic in this forum:

www.project-management-prepcast.com/inde...nt-of-the-pmbok#4382