Forecasting helps try to future events, and it has been used in every part of the world since recorded history.

People from different cultures use different methods to forecast. Some people use the movement of the moon or stars to predict the future, and others, palm lines.

In project management we use forecasting to predict the future performance of projects. However, here the forecasting is based on past performance and objective data, which provides fact based future progress estimates and give an early indication if anything may go wrong.

We commonly use three techniques in project management for forecasting:

- Estimate at Completion (EAC)
- Estimate to Complete (ETC)
- To Complete Performance Index (TCPI)

In this blog post, I’m going to discuss the Estimate at Completion in detail, and I will follow up in further blogs for the other two.

### Forecasting Technique #1: Estimate at Completion (EAC)

We know that real world situations do not always go as planned. There are many circumstances beyond your control that may alter your expected path and require a change in your planning.

As a project manager it will be your responsibility to manage these changes and evaluate their impact on the project objectives.

Now, the question is: how will you evaluate the impact of these changes?

You will evaluate it with the help of project forecasting tools, such as the Estimate at Completion (EAC).

The Estimate at Completion (EAC) gives you the forecasted value of the project when it is completed. With this data it can forecast how much you may have to spend to complete the project. In other words, it is the amount of money that the project will cost.

The Estimate at Completion can be determined by four methods depending on the way the project is performing. However, from a PMP Certification exam point of view, the first method is more important than the rest, and there is less chance that you will see questions based on the other cases.

Anyway, I’m going to explain all formulas mentioned in the PMBOK Guide, so don’t worry.

__Case-I: EAC = BAC/CPI__

In this scenario you assume that the project will continue to perform to the end as it was performing until now. Simply put, your future performance will be the same as past performance; i.e. the CPI will remain the same for the rest of the project.

##### Formula for the Estimate at Completion

In this case, the Estimate at Completion can be calculated by dividing the budget at completion by cost performance index.

Estimate at Completion = (Budget at Completion) / (Cost Performance Index)

Or,

EAC = BAC/CPI

From the above formula, you can conclude that:

- If the CPI = 1, then EAC = BAC. This means you can complete your project with your approved budget, and there is no need to use forecasting analysis.
- At the start of the project, the Estimate at Completion will be equal to the budget at completion, i.e. EAC = BAC.

##### Example of the Estimate at Completion (Case-I)

*You have a project to be completed in 12 months, and the cost of the project is 100,000 USD. Six months have passed and 60,000 USD has been spent, but on closer review, you find that only 40% of the work has been completed so far.*

*Find the Estimate at Completion (EAC) for this project.*

Given in the question:

Budget at Completion (BAC) = 100,000 USD

Actual Cost (AC) = 60,000 USD

Planned Value (PV) = 50% of 100,000

= 50,000 USD

Earned Value (EV) = 40% of 100,000

= 40,000 USD

To calculate the EAC, first you have to calculate the Cost Performance Index:

Cost Performance Index (CPI) = EV / AC

= 40,000 / 60,000

= 0.67

=>Cost Performance Index (CPI) = 0.67

Now,

Estimate at Completion (EAC) = BAC/CPI

= 100,000/0.67

= 149,253.73

Hence, the Estimate at Completion (EAC) is 149,253.73 USD.

In other words, if the project continues to progress with CPI = 0.67 until the end, you will have to spend 149,253.73 USD to complete the project.

__Case-II: EAC = AC + (BAC – EV)__

In Case-II, you have deviated from your budget estimate; however, from now on you can complete the remaining work as planned.

Usually, this happens when, due to some unforeseen, or one time conditions costs increased. However, you are sure that this will not happen again and you can continue with the planned cost estimate.

That is why in this formula, to calculate the EAC you will simply add the money spent to date (i.e. AC) to the budgeted cost for the remaining work.

##### Formula for the Estimate at Completion

The formula to calculate the Estimate at Completion in case-II is as follows:

Estimate at Completion = Money spent to date + Budgeted cost for the remaining work

EAC = AC + (BAC – EV)

##### Example of the Estimate at Completion (Case-II)

*You have a project with a budget of 500,000 USD. During the execution phase, an incident happens which costs you a lot of money. However, you are sure that this will not happen again, and you can continue with your calculated performance for the rest of the project.*

*To date you have spent 200,000 USD, and the value of the completed work is 175,000 USD.*

*Calculate the Estimate at Completion (EAC).*

Since the cost increase is temporary in nature and the rest of the project can be completed as planned you will use the formula:

Estimate at Completion = Money spent to date + (Budgeted cost for the remaining work – Earned Value)

EAC = AC + (BAC – EV)

Given in the question:

Actual Cost (AC) =200,000 USD

Budget at Completion (BAC) = 500,000

Earned Value (EV) = 175,000

Hence,

EAC = 200,000 + (500,000 – 175,000)

= 200,000 + 325,000

= 525,000

Hence, the Estimate at Completion is 525,000 USD.

#### Case-III: EAC = AC + (BAC – EV)/(CPI*SPI)

You are over budget, behind schedule, and the client is insisting you complete the project on time. In this case, both the cost and the schedule need to be taken into consideration.

#### Formula for the Estimate at Completion

The following formula can be used to calculate the Estimate at Completion in case-III:

Estimate at Completion = Money spent to date + (Budgeted cost for the remaining work – Earned Value)/(Cost Performance Index * Schedule Performance Index)

EAC = AC + (BAC – EV)/(CPI*SPI)

##### Example of the Estimate at Completion (Case-III)

*You have a fixed deadline project with a budgeted cost of 500,000 USD. So far you have spent 200,000 USD and the value of the completed work is 175,000 USD. However, as per the schedule, you should have earned 225,000 USD to date.*

*Calculate the Estimate at Completion (EAC).*

Given in the question:

Budget at Completion (BAC) =500,000 USD

Actual Cost (AC) = 200,000 USD

Earned Value (EV) = 175,000 USD

Planned Value (PV) = 225,000 USD

To calculate the EAC, first you have to calculate the CPI and SPI:

SPI = EV/PV

= 175,000/225,000

= 0.78

CPI = EV/AC

= 175,000/200,000

= 0.88

Now, you can use the formula:

EAC = AC + (BAC – EV)/(CPI*SPI)

= 200,000 + (500,000 – 175,000)/(0.88*0.78)

= 200,000 + 325,000/0.69

= 200,000 + 471,000

= 671,000

Hence, the Estimate at Completion is 671,000 USD.

#### Case-IV: EAC = AC + Bottom-up Estimate to Complete

This is the case when you find out that your cost estimate was flawed and you need to calculate the new cost estimate for the remaining project’s work.

Here you will go to the activity level, find the cost of each activity and sum them to get the total cost of the remaining work.

##### Example of the Estimate at Completion (Case-IV)

*You have a project to construct a government’s department building for 500,000 USD. To date you have spent 200,000 USD and the value of the completed work is 175,000 USD. However, during your project execution, you noticed that your cost estimation was flawed and you need to calculate your budget again for the remaining part of the project.*

*You sit down with your team members and re-estimate the cost of the remaining work. Your new estimate says that it will take 400,000 USD to complete the remaining part of the project.*

*Calculate the Estimate at Completion (EAC).*

Given in the question:

Budget at Completion (BAC) = 500,000 USD

Actual Cost (AC) = 200,000 USD

Earned Value (EV) = 175,000 USD

Bottom-up Estimate to Complete = 400,000 USD

In this case you will use the formula:

EAC = AC + Bottom-up Estimate to Complete

= 200,000 + 400,000

= 600,000

Hence, the Estimate at Completion is 600,000 USD.

### Forecasting Technique #2: Estimate to Complete (ETC)

Estimate to Complete is the second forecasting technique which is used along with Estimate at Completion. It is the amount of money needed to complete the remaining work.

Visit: Estimate to Complete

### Forecasting Technique #3: To Complete Performance Index (TCPI)

The To Complete Performance Index estimates how fast you have to move to achieve the target.

It is the estimate of the future cost performance that you may need to complete the project within the approved budget. This budget may be your initial approved budget (BAC), or a new approved budget, i.e. the Estimate at Completion (EAC).

Visit: To Complete Performance Index

### Summary

The Estimate at Completion is an excellent forecasting tool which gives you a mid-project estimation of the total cost that your project may take to complete. Please note that after you calculate the Estimate at Completion, you will need to initiate a change request to approve it. Once it is approved, this will be your new budget.

Here is where this blog post on the Estimate at Completion (EAC) ends. If you have something to say, share it through the comments section, and now you can move on to my next blog post on the Estimate to Complete.

If you are interested in learning all the mathematical formulas for the PMP exam, you can try my PMP Formula Guide. You can also try my PMP Question Bank to practice 400 PMP exam sample questions.

Hannah says

PMBok Guide has 2 other formulas for EAC:

EAC=AC+BAC-EV

EAC=AC+(BAC-EV)/(CPI x SPI)

Could you please explain these 2 formulas?

Fahad Usmani says

Hello Hannah,

Sorry to replying you late as I was busy with celebrating Eid Holidays with my family.

I have updated this blog post. Now it explains all EAC formulas mentioned in the PMBOK Guide.

Hope this answers your query.

Hannah says

Thanks Fahad, and hope you had a joyous Eid celebration with your family

Fahad Usmani says

You’re welcome.

Santosh says

How we can decide which formula should be used? e,g Instead of using BAC / CPI if I use AC + BAC – EV to calculate the EAC I get different answer for the same example which you have mentioned above. With first option, answer is $149,253.73 and with second option answer is $1,20,00 ($60,000 + $1,00,000 – $40,000 = $1,20,00).

Fahad Usmani says

I have explained it in detail. Please read the blog post again.

Shri M says

Hi Fahad

Do we generally take the Commitments when we calculate the Actual Cost ?(to elaborate, Actual Cost todate + Commitments= Total Cost). To arrive at Estimate at Completion, is it fair to consider the Total cost rather tahn the Actual cost (as its already commited for the project) and estimate to complete should be remaining work to be done excluding the commitments.

Please throw some light on this

Thanks

Shri M

Fahad Usmani says

Whatever you have spend is Actual Cost.

For the other part, I did not understand you question clearly. Please explain it again if you can.

Mohammad Baniode says

Valued comments.. keep going.. thanks Fahed

Fahad Usmani says

You are welcome Mohammad.

Kupa says

Loving the Study Notes section…Great job!

Paul Evans says

Found your site today in my PMP study time and wanted to say I really like your logical and simplifed approach.

Regards…Paul.

Paul Evans says

Sorry I also wanted to say that I’m looking forward to your next blog on ETC…Cheers…Paul.

Fahad Usmani says

Dont worry, you’re going to see many posts in future…

Karen Noakes says

Have a mock PMP question asking what the formula for forecasting EAC using remaning budget is and correct answer was EAC=ACC+BAC-EV.

Please explain as I cannot find this as an option in any of the 3 books I have nor can I find the ACC acronym stands for.

Fahad Usmani says

There is a typing error in your formula given by you.

Here is the correct formula:

EAC = AC + BAC – EV

ala'a says

Hi Fahad

just wandering in the EVM ,

we have the EAC=AC+ETC , then we have the EAC = AC+ (BAC- EV)

Finally e have the EAC = AC+ (BAC-EV)/CPI

How was that driven?!

thanks much indeed for your support

Ala’a

Fahad Usmani says

For the exam it is sufficient to know the formula, derivation of formula is outside the scope of the exam.

Sutanu says

Hi Fahad,

Can you explain about the TCPI (To Complete Performance Index)?

Thanks in advance

Fahad Usmani says

It is explained here:

https://pmstudycircle.com/2012/05/to-complete-performance-index-tcpi-in-project-cost-management/

ken says

Thanks Fahad, it s cant get any simpler that how you explained the 4 different types of EAC. You gave me a very clear explanation and I am confident that I understand when and how to use each formula. Thanks.

Fahad Usmani says

You’re welcome Ken.

ala'a says

yes indeed the article is simple and very elborative

Fahad Usmani says

Thanks Ala’a.

Mohan says

I just found your site today in my PMP study and would like to say thank you for your logical and eloborated information.

Fahad Usmani says

Thanks for your comment Mohan.

Mohamad says

Thank you for explanation, but the scenario of using SPI and CPI together is not clear, how SPI*CPI means that you’ll be on schedule?!

Fahad Usmani says

These two are different parameters. For schedule performance, you will only look at SPI.

ala'a says

Dear Fahd,

on the same context , would you kindly send me some few various scenarios that might be encountered in the PMP EXAM on CPI, TCPI , EV , CV and SV , ETC and BAC

thanks a lot

salam

ala’a

Fahad Usmani says

These topics have already been explained on this blog.

Please refer below given blog post:

https://pmstudycircle.com/2012/05/fast-forward-earned-value-management-evm-forecasting-tcpi/

Tauseef Qureshey says

Regarding EAC 3rd case that is following

EAC=AC +(BAC-EV)/CPI*SPI

Here we calculate EAC that is in terms of budget or money or cost (i.e it will give you new budget,money or cost). But how we can find EAC in terms of schedule or time( i.e in terms of new schedule or time) such as how much more schedule or time required to complete remaining work.

Thanks

Fahad Usmani says

EAC is calculated for the budget.

For schedule you can use To complete schedule performance index, and SPI.

John Phillips says

How would you go about finding estimated time to completion, thanks

Sameh says

Dear Fahed

great efforts as usual , i appreciate your efforts and your smooth explanation but if you don’t mind i have some questions:

1- in Case no 1 , it has not been mentioned that CPI will be the same to the end of the project in the problem , so if i face same problem in the exam how can i guess that CPI will be the same to use this formula ?

2-in case no II , as you have highlighted that we can complete the remaining work as planned , what does it mean ? I understood that BAC has to be the same until the end of the project , it means the value of BAC has to equal the EAC !! or how we can complete the remaining work as planned ? and finally you calculated EAC is 525000 while BAC is 500000 ! , so how we completed the remaining work as planned ?

Thanks in advance

Best regards

Fahad Usmani says

For case-I, I have already written that:

“In this scenario you assume that the project will continue to perform to the end as it was performing up until now”.

In the second case you have over spend till certain point, however, after that you can complete that tasks with previously estimated cost.

Basem Fayed says

Dear Fahad,

A mathematical example of Estimate at Completion (Case-III)

However, as per the schedule you should have earned $225,000 USD to date.

Why earned,I believe it should be planned value PV

Fahad Usmani says

Yes, it is planed value.

Basem Fayed says

Dear Fahad,

If it possible to explain the following

what is the logic behind using $ ( Money value ) to measure time,i.e. using PV in the equations ( SV=EV-PV) to indicate that we are behind or ahead of schedule

Thanks and regards

Fahad Usmani says

Then tell me how are you going to measure the schedule?

Basem Fayed says

logic wise we measure length in meter,Foot…etc

and time in Hours,days,…etc

schedule measured in …. time

the results of SV should be measured in “time metrics”

So why the person who invented the Earned value management….considered planned value = $ ..i.e. Money…..and the results are behind schedule or ahead of schedule show time?

Fahad Usmani says

Earned Value Management is all about the money, it is about how much have you spent and earned and how are you progressing in $ terms.

Basem Fayed says

Thank you for the explanation.

going through the internet I got the logic behind PV.

Sorry if I caused any inconvenience

Fahad Usmani says

No problem Mr Basem.

deepak says

Can you please let me know why project schedule is input for determine budget process. It is planning process so why we are not using schedule baseline as input.

Tulika says

IF you read Rita, it says (and real scenario too) the cost of procurement (services or resources) may also vary on the “time of year” , eg raw material for cap may be expensive during winters , so overall cost of woolen production will go high if you choose to procure during winters , thus it is considered while determining budget.

Hope my understanding is correct .

Fahad Usmani says

Yes.

Hardeep says

Hi Fahad,

Saw this pmstudy and it explains formula’s very well. I have a query regarding

Case-III: EAC = AC + (BAC – EV)/(CPI*SPI)

You are over budget, behind schedule, then you use (CPI * SPI) both

a) How about if only over budget (within schedule) — Should we use only CPI at bottom ? –>> EAC = AC + (BAC – EV)/CPI

b) How about if only behind schedule (within budget) — Should we only use SPI at bottom ? —>>> EAC = AC + (BAC – EV)/SPI

Does that make sense? Please let me know . Thanks

Fahad Usmani says

If you are over budget and within schedule you can use either case-I or case-II.

EAC is for cost estimation. If you are within budget and behind the schedule, you will go for schedule compression technique to bring project on schedule.

Saud says

See references Marked for review

61. You are performing earned value technique on your project.

After budget approval, an additional and unexpected cost item has been identified, which made the project more expensive some weeks ago. The item has meanwhile been paid by the project team, and it is expected that for the remaining duration of the project, costs will be as budgeted.

In this case, which is the best formula to calculate EaC (Estimate at Completion)?

1 EaC = BaC – CV

2 EaC = BaC / CPI

3 EaC = AC + BtC / CV

4 You can not compute the EaC.

Reshma says

Dear Fahad,

Thanks for the detailed explanation.

I am confused with some calculation and need guidance.

In the 1st example(1st case) where EAC = BAC/CPI, BAC = 100000, EV = 40000 and AC = 60000. CPI = 0.67 thus EAC = 100000/0.67 = 149253.7

But if we calculate it in another way EAC = 100000/(40000/60000), as per cross calculation EAC = (100000 * 60000)/40000 = 150000.

We get accurate values for normal equations like 5/(2/10) which can be 5/0.2 still 25 and 5*10/2 still 25. Here i am unable to understand the reason for this difference.

Can you guide !!

Regards,

Reshma

Fahad Usmani says

I took the round figure in decimal for CPI, that is why you are seeing this difference.

Jack Miclat says

Fahad,

When can we apply these formulas?

EAC= AC+(BAC-EV)/CPI*SPI

EAC=AC+(BAC-EV)/CPI

EAC=BAC/CPI

EAC=BAC/CPI*SPI

Fahad Usmani says

All three formula mentioned in the PMBOK Guide has already been explained in this blog post.

shay says

Hello Fahad

I could not pass my PMP in first attempt. I am studying again. The exam is changing after Jan 11th. What would be your suggestion about changes coming up. Should I try to give exam before or after. Kindly advise.Thank you

Fahad Usmani says

One month time is enough to prepare for the second attempt. You can try it before the exam changes.

Haz says

You are great!

Thanks Fahad, you’ve been very helpful during my preparation, I’m having my exam in 3 days, will come back to thank you again after I pass inshalla,

Fahad Usmani says

Good luck on your PMP exam.

zubair says

when you say a project is complete?

a) budget at completion is equal to earned value

b) Earned value is equal to Cost value

write the most authentic relationship

Fahad Usmani says

When the project is completed, earned value is equal to planned value.

When you revise the budget, your EAC will be your new BAC.

Roger H. Mandel says

I have been teaching and accomplishing Earned Value Project Analysis for over 20 years and I do have some spreadsheets for the development of IEACs.

Your for the asking.

Fahad Usmani says

Thanks Roger for asking. You can send them at fahad@pmstudycircle.com

Gulzaib Khan says

Suppose we are executing a project and at a certain stage, CPI is closer to 1, but now onwards, for remaining part of the project, our Item Rates are below the Technical Sanctioned Estimate, which themselves are not practically feasible.

It means our Actual Cost would increase as compared to our Earned Value which concludes our project would not follow the preceding trend.

In this Scenario, how would we calculate EAC ?

Kindly guide.

Fahad Usmani says

As your estimate is wrong, surely you will correct it.

Gulzaib Khan says

Working as a Contractor with signed contract agreement, estimate can’t be altered. Please guide in this scenario.

Fahad Usmani says

If it is a fixed priced contract, the cost cannot be changed.