September 28 & 29, 2020 | Virtual
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It probably tells you something if it is not in the current PMBOK, like maybe it's not widely used. Perhaps it will be in the 6th edition, and then we can take more notice of it.
Had no idea about this - I thought you might have been confusing it with Earned Value Management. But then I looked into Google and Wikipedia return this nice entry:
Indeed, I always found confusing that SPI is 1 at the end of a project, even if it has experienced major delays. One may argue that towards the end of the project, the SPI becomes less relevant, but yet, I found this new approach interesting. Thanks for bringing it up.
I use it and you can find it inside the PMI´s EVM Standard. I use it before it appears into the standard because EVM is based on cost and SVM is based on work progress so it is better for those cases where you have no cost information to calculate the EVM variables (in my case, after more than 30 years in the field, I could say that was in my personal work life 90% of times). In fact, I have teached it lot of times including in Universites courses. So, you can take advantage of it. You can find lot of good information into the internet mainly because USA DoD and NASA have used it.
To add to the discussion.ESM was developed as an extension of EVM. You can find more info about ESM at: http://www.earnedschedule.com.
SPI=EV/PV so at completion SPI=1 even if the project was delayed, which is very counter-intuitive. As a PM you need a fair KPI that relfects the status of your time-based schedule performance. So in case of a delayed completion, you need an schedule performance indicator that faithfully reflects that. The EVM SPI does not do that.
So schedule performance index is a bit of a misnomer in my opinion. It suggests a schedule (time) indicator whereas it is related to planned work instead. Therefore, I call it Scheduled work (cost) performance index.
There are academic sources that suggest that the SPI is a decent schedule (time) indicator at about 20% completion. Beyond 20% completion, the SPI can vary wildly before it returns back to 1.
I used ESM in my project and adopted the SPIt indicator. What I need is a faithful report of the project's actual time-based schedule performance compared to my planned schedule. Moreover, I want the schedule performance indicator to help me make timely decisions to keep the project on track. EVM's SPI can only help that much.
Earned Schedule is an extension of Earned Value Management. It is introduced in PMPOK Guide, 6th edition.
The traditional EVM approach is based on cost. All parameters, PV, AC and EV are all derived from cost. Due to this, traditional EVM approach has several limitations.
1. Schedule Variance is in terms of dollars - difficult to interpret
2. When a project is completed, SV is always 0 and SPI is always 1. This is independent of actual schedule performance of the project.
3. There is no means to forecast schedule in traditional approach.
To fix these limitation Earned Schedule is introduced.
Time, not cost, is the focus of Earned Schedule.
If you wish to understand the basic have a look at the following.
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