Schedule Performance Index (SPI) and Cost Performance Index (CPI) allow you to assess the project’s performance.
Schedule performance and cost performance are the two most important parameters of your project. SPI and CPI help you analyze the efficiency of any project.
Management is always looking at these parameters for any deviations from the baseline. Deviations from the baseline cost a great deal in project management. Therefore, it is important that you understand these concepts well.
由于这些概念涉及数学计算，因此许多有抱负的人忽略了它们。一旦您了解了数学，就可以轻松解决PMP考试的问题。
Schedule Performance Index (SPI)
The Schedule Performance Index (SPI) shows how you are progressing compared to the planned project schedule.
根据PMBOK指南，“计划绩效指数manbet最新版（SPI）是对计划效率的衡量标准，称为赚取价值与计划价值的比率。”
计划绩效指数为您提供有关项目时间效率的信息。
The Formula for the Schedule Performance Index (SPI)
You can find the Schedule Performance Index by dividing Earned Value by Planned Value.
Schedule Performance Index = (Earned Value) / (Planned Value)
SPI= EV / PV
You can conclude that:
如果SPI等于一项，完成的工作等于计划的工作；该项目按计划进行。
- You have completed more work than planned if the SPI is greater than one; the project is ahead of schedule.
- If you have completed less work than planned work if the SPI is less than one. The project is behind schedule.
- 如果SPI等于一项，完成的工作等于计划的工作；该项目按计划进行。
确保在计算时间表绩效索引时考虑所有任务。有时，您只能考虑critical pathand ignore the rest, which will give you an incorrect result.
Therefore, make sure that non-critical activities are included.
Example of Schedule Performance Index (SPI)
You have a project to be completed in 12 months, and the budget is 100,000 USD. Six months have passed, and 60,000 USD has been spent, but upon closer review, you find that only 40% of the work has been completed so far.
Find the Schedule Performance Index and deduce whether the project is ahead or behind schedule.
Given in the question:
Actual Cost (AC) = 60,000USD
Planned Value (PV) = 50% of 100,000 USD
= 50,000美元
In the question, the Planned Value is not given. However, the project duration is 12 months and 6 months have passed. In this situation, you can assume the budget was distributed evenly for each month. Therefore, in 6 months, 50% of the budget will have been spent.
Earned Value (EV) = 40% of 100,000 USD
= 40,000美元
现在，
Schedule Performance Index (SPI) = EV / PV
= 40,000 / 50,000
= 0.8
Hence, the Schedule Performance Index is 0.8
You are behind schedule since the Schedule Performance Index is less than one.
Cost Performance Index (CPI)
The Cost Performance Index helps you to analyze the cost efficiency of the project. It measures the value of the work completed compared to the actual cost spent.
根据PMBOK指南，“成本绩效指数manbet最新版（CPI）是预算资源的成本效率的衡量标准，其表示为获得的价值与实际成本的比率。”新万博登录手机版
The Cost Performance Index specifies how much you are earning for each dollar spent on the project. It shows how well the project is sticking to the budget.
The Formula for the Cost Performance Index (CPI)
You can calculate the Cost Performance Index by dividing the earned value by the actual cost.
成本绩效指数=（赚取价值） /（实际成本）
CPI = EV / AC
You can conclude that:
- You are earning more than what you have spent if the CPI is greater than one. The project is under budget.
- You are earning less than what you have spent if the CPI is less than one. The project is over budget.
- Earning and spending are equal if the CPI is equal to one. You can say that the project is proceeding as per the planned spending.
Example of Cost Performance Index (CPI)
You have a project to be completed in 12 months, and the budget of the project is 100,000 USD. 6 months have passed, and 60,000 USD has been spent, but upon closer review, you find that only 40% of the work has been completed.
Find the Cost Performance Index for this project and deduce whether you are under budget or over budget.
The following information is given in the question:
Actual Cost (AC) = 60,000USD
Planned Value (PV) = 50% of 100,000 USD
= 50,000 USD
Earned Value (EV) = 40% of 100,000 USD
= 40,000美元
现在，
Cost Performance Index (CPI) = EV / AC
= 40,000 / 60,000
= 0.67
Hence, the Cost Performance Index is 0.67
This means you are earning 0.67 USD for every 1 USD spent since the Cost Performance Index is less than one. This means you are over budget.
You have studied variance (SV and CV) and indexes (SPI and CPI). If you think that both sets of parameters provide the same information, you are wrong.
Both are required because there is a difference between variances and indexes; the former provides you with the difference between the two values and the latter gives a ratio.
The result comes in dollar form in cost or schedule variance. A negative variance means the project is in trouble. However, the project is in good shape if the variance is positive. The problem with variance is that you cannot compare the health of the project with another, even if your organization has many projects.
Therefore, you use the Performance Indexes to compare the health of a project among many projects. The Performance Index is the ratio between the parameters, and a glimpse of these ratios will help you determine the health of the project. This makes it easier for you to compare the relative health of projects. You can find efficiency through indexes.
成本绩效指标和进度dex Comparision Table
成本绩效指标和进度dex Comparision Chart
Summary
安排性能指数和成本绩效指数可帮助您分析项目的进度。这些措施可以帮助您确定是否符合标准。如果比率高于一个，您的状况很好。如果比率少于一个，则该项目存在问题，您应该接受corrective action. In ideal conditions, the ratio should be one.
This blog post is the fourth in a series of seven on Earned Value Management and project forecasting. Please read through my previous three posts before reading this post if you’re coming here from a search engine or a referral.
The following are the links for other blog posts:
- Earned Value Management
- Elements of Earned Value Management
- Budget at Completion in Project Management
- Cost Variance in Project Management
- Schedule Variance in Project Management
- Cost Performance Index in Project Management
- Schedule Performance Index in Project Management
- Schedule Variance and Cost Variance
- Schedule Performance Index and Cost Performance Index (You are here)
- Estimate at Completion
- Estimate to Complete
- To Complete Performance Index
我的问题。现在一天每个项目管理t organization has Project Control department which also focus on cost and schedule and same thing is the primary responsibility of project manager. what is the primary difference between project manager and project control manager. Please elaborate.
If our cost performance remained 0.95 for the first three months, what will be our course of action as a project manager?
我有个问题。如果我们两个月的成本表现保持1.07，那么作为项目经理的行动将是什么？
One of the critical tasks of a project is laying an electrical cable 60,000m in length. So far, 30,000m has been laid, so actual work is 30,000 of 60,000m. The budgeted cost for the task is $90,000. The actual expenditure so far is $60,000. The task duration is 10 weeks, and work on this task started 7 weeks ago.
1. Calculate the Planned Value (PV)
2. Calculate the Earned Value (EV)
3. Calculate the Schedule Performance Index (SPI)
4.计算成本绩效指数（CPI）
哇，谢谢您，先生，这是一个很好的解释。我以一个很好的方式明白了这个想法。
项目结束时以下哪个理想；一种。AC = EV。b。EV = PV。C。AC = PV。d。CPI = 1
At the end of the project you will earn all planned value, so as per my understanding EV = PV will be the right answer.
Hello,
If you have a project that is complete and the CPI=1 and the SPI=237 on an expedited project is this a valid way to represent that the project completed significantly ahead of schedule?
Are you sure that SPI = 237?
If SPI = 2 this means you have completed the project in half time.
When I look at the formulas and the examples, it seems to assume that costs are spread evenly throughout the project (eg. 3 consultants working from start to finish of the project).
but in fact most projects have costs varying from month to month. eg. there may be purchase of software or equipment that spikes costs in certain months.
EV，PV CPI等会准确涵盖这些情况吗？
In that you will see your schedule to find the value of PV, you have the AC, and you can find the EV. Once you get these figure, you can run your analysis.
如果你提前计划,为什么你没late SPI..You should party till next milestone arrives. :)
如果差异很小，则可以，否则您必须找到其原因。
the key to calculate spi/cpi at work package level is to know the percentage completion of work package. for example – planned efforts are as follows for each work item – requirement gathering = 40 hrs, design = 100 hrs. Build and Test = 200 hrs. %completion of each work item, requirement gathering = 100%, design = 40%, build and test = 20%. So, work package completion can be calculated as – (40*1+100*0.4+200*0.2)/(40+100+200) = 120/340 = 6/17 = ~30%.
once you know the percentage completion at package level, you can calculate spi/cpi at package level by summing up efforts of each items and considering earliest start date and latest finish date of the project/package.
Well said Alam.
亲爱的法哈德，
感谢您的博客。我刚刚开始阅读PMP材料，这确实得到了很好的解释。
但是我对此完全混淆了，例如我只是理解概念。在现实世界中，这种情况似乎是不可能的，与此同时，它也为我提出了一个问题。
If i try to make this real, as an eg. i have to consider EV & CV as 20000 and PV as 80000. This means that i had considered 80% completion of work when actually only 20% has been completed. This is really bad but we say that having CPI > 1 means we are on schedule. Aren’t these 2 scenarious completely contradictory. Here we are saying that Cost spent is as per expectation but projection which has been done (PV) is completely wrong. Thus how can CPI justify perfectness of project schedule or even mean that cost is being spent as expected.
Please guide !!
Thanks and Regards,
Reshma
There is a difference between real world situation and virtual data. While making a question, you may select any virtual data to check the analytic skill of a candidate. You should not worry about it.
another question please :
In calculating EV i use % complete in terms of quantity, ex. we have a planned quantity of 1000 cubic meters of reinforced concrete to be finished in 8 months with BAC of 6000000 , as to date we completed 100 cubic meters so the EV = 0.1(100/1000) * BAC
is this right and accurate ?
Regards
让我们使用简单的数学。
The cost of 1000 cubic meter concreting is 6,000,000 USD.
This means cost of 1 cubic meter concreting will be = 6,000,000/1000
= 6,000 USD
Therefore, the cost of 100 cubic meter concreting = 100 *6,000
= 600,000 USD
Hope it helps.
Yes sir it really helped
Thanks a lot!!!
But sir can SPI & CPI be 2 or more or can it be negative?
And sir what will be the CPI & SPI to the same problem
If the same activity was to be completed in 20 days but it got completed in 140 days
SPI and CPI depends on EV, PV and AC. These are ratios and can not be negative.
Regarding your next doubt, you can analyse it with same logic.
Thank you sir…but cal elaborate a little…
Can SPI be 2?
And for the second question
Is SPI = 20/140 = 0.14
ACC逻辑？
The logic says, SPI = EV/PV
Mathematically you can come with any number and get the result.
Great explanation Fahad !
One question I have..
If SPI is less than 1.. say 0.6… of course it means we are behind the schedule..does it always mean that deliverable have not been met ?
Can it be possible that project is complete with all deliverable accepted by customer.. but SPI is still 0.6 ?
Thanks
Deliverable can be met even if the project is behind schedule.
It is not possible to complete the project and spi is still 0.6 because once the project is complete, no work left and spi = 1.
How is that possible Fahad – Deliverables are met, but the project is behind schedule? Can you elaborate?
Suppose you are working a multi-year project, and you have to deliver some deliverables at some intervals.
And if you deliver a few of these deliverables late, you will say that although the deliverables are met but the project is behind schedule.
Still could not get it. Let us a say Project X has 3 deliverables – D1, D2 and D3. D1 will be on Day 15, D2 will be Day 30 and D3 on Day 45.
If I am saying on 45th Day that D3 will be delivered on Day 50, then – Project is behind schedule. But are the deliverables met? No. Then saying that D3 is met – is not it wrong?
In such a case – yes, D1 and D2 are met and SPI will be 1 for them, but will be D3 be of SPI = 1? And more importantly will project be at SPI = 1? No. As Cumulative SPI will pull it below 1.
Or am I understanding differently?
Yes, you’re right.
In this case you were proceeding in correct direction until you deliver D2, however, after delivering it you deviate and the schedule is delayed.
Thanks Fahad.
正确的措辞将是 - 项目可以延迟，SPI可以＆将低于1，但是可以满足某些可交付成果，但不是全部。当我第一次阅读时，感觉就像“项目可以延迟，但可以满足可交付成果 - 意思是全部”，事实并非如此。
Btw, what will be you take on CPI in such a case for D1, D2, D3 and the complete Project after the project is delivered (i.e.,delayed and delivered)? Will it be 1 for all or different?
Regarding CPI, you need to see how much you have earned and how much has been spent.
I have spi and cpi
1我的老师说为什么spi和cpi是坏?(或why cpi , spi bad indicator ?)
2-替代方法[CPI，SPI]哪种方法？
Thanks
SPI and CPI are just an indicator that in which direction your project is leading. CPI and SPI are good or bad, it depends in condition of your project.