Say I have a project X that is due to be complete by Date Y Right now we are 10% behind schedule (Should be say 50% and right now 40%), How can I estimate what level of "effort" is required to catch up?

I.E. the original schedule expected 1% of units of work a day to be done, but to catchup to the schedule by some date Z (which is <= Y), we need to work 1.2% units of work a day, I'm looking for a way to identify the 1.2% units part based on an existing schedule.

I'm not sure what this is called but if someone that has editing rights has a better idea for the phrasing, I would be grateful if they could reword it.

Hoping this doesn't make it a "tool recommendation, or shopping question", again reword if it sounds like it, however if you know how to find the above information using tool, can you please provide a "how to" on that tool, this is really what I'm looking for, my project is currently using MS-Project, but I don't think it would be too tricky to insert "start/end dates" into another tool, if it has this feature? I would ultimately like to be able to run a report estimating what "units of work per day" are required to complete the entire project, broken down by tasks that are behind only.

  • Welcome to PMSE! Shopping questions are off-topic here per our FAQ, so I edited your question lightly to remove the shopping portion. I think you have an otherwise interesting question that I'd hate to see closed just because it looks like a tool-shopping question.
    – Todd A. Jacobs
    May 16, 2013 at 12:38
  • Thank you for the info, a collegue mentioned that MS-Project might be able to do what I was looking for, but I can't find any documentation explaining if it's possible, I was originally going to ask about MS-Project only, but decided I didn't want to limit myself in the event another tool was able to accomplish the task. I hope that explains why I worded it the way I did initially. May 16, 2013 at 12:53
  • My concern is that the response to my question will result in a "take y-actual divide by days" which is not what I'm looking for, (I can do that, but for a large project with multiple slippages, it might be nice to have a single report with each slippage and estimated increase of units of work per day to catch up) May 16, 2013 at 12:54
  • I've added some additional "commentary", if this question is still a shopping question, could you please provide a place I can ask the above type question to get an answer? If I can find the info somewhere else, then you're welcome to edit and remove any references to tools in my question. May 16, 2013 at 13:00
  • How can you be sure your estimates are true? Have you tried to determine the causes of observed discrepancy? May 17, 2013 at 20:12

4 Answers 4


I'm not sure that I understand the question, but it sounds to me like you're asking for the To Complete Performance Index or TCPI.

Roughly speaking, the TCPI answers, "How far behind are we, and how much are we going to have to accellerate in order to make our deadline?" The TCPI is TCPI = (Work Remaining)/(Budget Remaining)

Of course that assumes that you've quantified the work to be performed and the work that has been done. If you didn't set up earned value when you did your WBS/WBS dictionary, and/or you didn't review it when the task started, then TCPI won't help you in the slightest.

As the estimable @codegnome has pointed out, knowing how much faster you need to work doesn't really tell you how to work faster. What activities can you drop without causing a loss of quality? Which staff members can you terrorize into overtime without damage to overtime & employee relations?

  • I think this is exactly what I am looking for, I did a search for that, and it appears that MS-Project supports it, However, it doesn't give very "detailed" information. I am kinda looking for a "daily" increase, not an overall task performance ratio? (I'm the worker bee, and this is information I personally would find useful for me to have goals to look to) May 16, 2013 at 14:57
  • 2
    TCPI is a valuable indicator; however, its use is around validating the EAC. For example, if your CPI is 0.88, which means you are overrunning, and your TCPI is 1.25, this means you have to be operating at an efficiency level of 1.25 from here on out to meet your EAC. Since 0.88 and 1.25 is a huge spread, then you would conclude that the EAC is NOT credible, not real. The general rule is, your TCPI should not be greater than 10 points from your CPI. This is a cost indicator, not a schedule indicator, too. May 16, 2013 at 15:10
  • Looking at what I can do to improve quantity output per day, will tell me if it's enough, per se. (I am not looking at this from a "How much OT can I work to get X done" perspective, it's more of a productivity goal, whether by means of working faster, or by better use of tools). May 16, 2013 at 15:27
  • 2
    That's true and I agree. TCPI is around costs, however, so I am not sure if it is a valid indicator for schedule. Earned Schedule is a derivative of Earned Value but I do not know if there is a TCPI equivalent in ES. May 16, 2013 at 15:48
  • 2
    Excellent question @DavidEspina. If we followed the same format as other values, it would be (Work remaining)/(Time Remaining), which is almost tautological. Of course the key is to define (work remaining). I'm still struggling to understand the "daily increase" part of the question.
    – MCW
    May 16, 2013 at 16:28

If you determined where you are by using earned value and your EVMS is credible, you can apply this formula:

ECR=(BAC-BCWP)CAR*remaining PoP in years


CAR=(BAC/Planned FTE)/PoP

This should result in the level of FTE at which you will need to operate in order to catch up to the schedule by the end of the PoP.

You can run this same formula, replacing BCWP with ACWP, to figure out what FTE burn you need to catch up from a cost variance.



Period of Performance (PoP) = 2 years or 104 weeks; Hours = 24,000; Planned FTE = 6; Budget at Completion (BAC) = $21,600,000; Weeks exhausted = 29; Weeks Remaining = 75; Budgeted Cost of Work Performed (BCWP) = $5,900,000; Budgeted Cost of Work Scheduled (BCWS) = $6,023,077; Actual Cost of Work Performed (ACWP) = $6,200,000; Schedule Performance Index (SPI) = 0.98; Cost Performance Index (CPI) = 0.95; Actual FTE = 6.18

Following the formula above, the ECR = 6.05.

This suggests you need to run at 6.05 FTEs versus the 6.00 FTE planned or the 6.18 actual FTE.

However, 6.05 is less than 6.18 so it does not make sense that "dropping" to 6.05 will cure your schedule when you were late at 6.18. So you need to interpret carefully, meaning you may need to add 0.05 FTE to your 6.18, making it 6.23 to correct the schedule.

We also know that crashing your schedule does not always result in making things better but worse. Nevertheless, this is the math. Use it with care.

  • I'm not a PM so quite a few of the acronyms are over my head, however my wife is familiar with EVMS so I may have to bug her :) May 16, 2013 at 15:23
  • I spelled out some of the acronyms; however, I cannot remember what ECR or CAR stand for. Sorry. May 16, 2013 at 15:42


Identify a root cause for the slippage, re-estimate your level of effort for each task, and adjust your schedule accordingly. You can't identify the cause of a slippage from a schedule; at best, you may be able to identify the process or task dependency that's holding back your project.

Problems with Percentages of Units of Works

There are some problem domains where you can usefully quantify percentages of units of work, but in general this is now accepted as a Bad Idea™. In manufacturing, for example, you can safely say that if you have three tires attached to a new car, then your wheel task is 75% done. In most endeavors, though, making a broad statement like "100% of tasks are 40% done" is not really very informative.

What You Should Do

You should do a few basic things before proceeding. First is to identify why your schedule is slipping. Accelerating your schedule on paper will not necessarily accelerate your completed work. To do that you need to identify the cause of the slippage, and determine whether you have:

  1. a process problem,
  2. a resource constraint,
  3. an unrealistic schedule, or
  4. some other hidden issue that needs to be brought to the surface.

Once you've identified the problem and gathered buy-in for a solution, you can then adjust your project plan based on updated plan elements. You have a number of choices there, too:

  1. Reduce scope to meet the current deadline.
  2. Add resources to meet the current deadline, although you should keep Brook's Law in mind.
  3. Modify your deadline to reflect what you've learned about your project's process and resource constraints.

What Not to Do

What you should probably not do is press some magic "Go Faster™" button based on an accross-the-board accelerated schedule. Shortening every task by 2/10ths of a percent is unlikely to yield useful results.

Think about it this way. If I have a 4-hour task that I've decided is 1.2% behind schedule, that means I'm running a little less than 3 minutes per person behind schedule for that task. Let's say it's assembly-line work, and I speed up the assembly line by 0.2% (miles per hour? widgets per second?), possibly increasing the error- or stop-work rates in the process. Having done so, which 172.8 seconds of that 4-hour process are the waste that I expect each person to eliminate?

  • Sometimes having "goals" helps to make it clearer what you're trying to accomplish, however we have a lot of little widgets and people aren't always working at 100% productivity, so asking that they "try" to meet a goal each day at least gives guidance. Suppose I told you that you had to lose 50 lbs by next January. Suppose you needed to lose 1 lb a day, but the first 5 days you lost .5 lbs, you'd like to know what you need to do per day to get caught up right? Maybe you'd choose different exercise routines to accomplish that goal when you're behind. That's what I'm trying to go for. May 16, 2013 at 13:52
  • Simply saying "you're 50% behind schedule" doesn't help, it isn't "actionable" saying increase your output by 2 "units" per day and we should make it, is actionable. Unless you have an idea what you're going for, just saying you're 49% behind schedule the next day doesn't tell you if you're going to meet or miss the mark. May 16, 2013 at 13:53

I completely agree with CodeGnome. Actually "we are 10% behind schedule" can only have a "statistical" meaning and statistics are usually applicable to large data set only -> very fine grained task definition, or a huge project that is out of my experience. Probably your is the latter case, but in my projects I had big trouble to identify a creep of 10%. Actually my tool identify creeps and also tries to adjust the work plan, but usually the problem cannot be solved "going faster". I work in a agile oriented way with a very motivated team, when we are behind schedule, is because the schedule is wrong :-). Overworking never helped us.

  • In this case "motivation" is what I'm aiming for, tell me what I need to accomplish so I know how to complete in time, when we're behind, now I don't know what I need to accomplish on a daily basis to help the overall goal if that makes sense. May 16, 2013 at 13:55
  • how do you measure your progress? (sorry if this question seem stupid to you :-) )
    – Roberto
    May 16, 2013 at 14:02
  • Average completion of all units (within the task). (no problem) Each task is not a unique unit, it's a set of units. May 16, 2013 at 14:35

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