Confusing Questions and Answers

Question: In your construction project, the CPI is 0.85 and SPI is 1.25. What could be the possible reason? 

  1. A critical resource went on sick leave for a long period of time, which had not been anticipated earlier.
  2. The cost of raw materials required for construction increased by 10%. - You had anticipated a cost increase of 12% in your project plans.
  3. In anticipation of delays, the project was crashed to decrease the duration.
  4. There was four days waiting time in the curing of concrete, and work could not be done during that time.

Justification:Option 3: This is the correct answer, because crashing of a project results in decreased duration and increased costs. This verifies the given data on CPI and SPI.

Options 1 and 4: They are ruled out, because they do not verify the given data that SPI>1.

Option 2: This is also ruled out, because it does not verify the given data that CPI<1. 


                 As project was crashed the CPI should increase in case of cost, the project was crashed for Duration. Is it true or other jutification. ?

 Your project is in the execution stage. NPV of your project is -$200,000 and IRR is 5%. CPI is 1.2 and SPI is 0.8. What is the recommended action?

  1. Cancel the project since NPV is negative
  2. Cancel the project since IRR is very low
  3. Crash your project
  4. Try to improve the NPV

 In this question You're in execution and Npv and irr project selection techniques ... Low spi makes more sense to be worried about so you'd use schedule compression such as fast tracking or crashing

  In your project you had planned to have Tasks A, B & C completed already, however tasks A, B, C, and D are 100%, 80%, 0%, and 0% complete respectively. The value of each day of work is $100. Using the 0-100 Rule and the information given below, calculate the SPI: 
Tasks A, B, C, and D have duration of 3, 5, 4, and 3 days respectively. 

  1. 0.25
  2. 1
  3. 0.50
  4. 0.75

Please tell your problem

Hi SS Pawar

Going by the 0-100 rule answer should be (3*1 (100%) + 5 * 0.8 (80%) )/14 =7/14= 0.5

Pls suggest how did you get 0.25


Option 3 will be the answer, because In anticipation of project will be delayed, they crashed the project and thus extra expenditure done, and hence AC increased, thus CPI has been lower than 1. And Work achieved earlier than planned date, and SPI has gone up.


Option 3will be answer because

Since the project is under execution and at this stage project will not earn money, hence by default NPV will be minus. Also asset value not be considered much higher hence IRR will be low as 5%.

Other information is given CPI is higher and SPI is lower than 1, Hence by crashing the project ,planned schedule could be achieved.


Project task A, B and C is planned for a point of time, and total schedule days for these 3 tasks are given 3+5+4 = 12 days.

*While following 0-100 rule, only Task A will be considered completed.

One day work value for each task for every day is given 100$.


PV12 = 100$ x 12Days =1200$

EV12 = 100$ x 3Days =300$

SPI12=  EV12 /  PV12 = 300/1200 = 0.25

* (0-100 rule means, if any measurable item -like work/task/activity/deliverable/control account/work package, has been completed 100% , only will be taken in account of update or progress, and thus 0 to 99% completion will be considered as zero progress.)

Hi SSpawar

In ques 3 you have not considered task D which the question creator provided in the original post hence i doubt 0.25 can be the correct choice Also i believe there is a subtle difference b/w 0-100 rule and 100% rule ...0-100 rule means calculating weightage as per the percentage completed and its not 100% rule in purest sense which you rightly said considers only tasks which are 100% completed but here question states 0-100 rule not 100% rule

So to conclude taking Task D's duration also and weightage of both Task A and B 0.5 seems to be the correct answer

P.S I dont intend to contradict .I may be wrong but wanted to ensure all aspirants get correct picture by our experience



Puneet, Question is little tricky,

Information are given there extra than what required. In 1st line, he has planned for A, B and C only, and asking SPI for that only.

Regarding rule:

Please refer this pages

Page 240- RITA 7

Progress Reporting PAGE 185 The project manager can use information –

------------ The project manager can use one of the following practices to report progress:

50/50 Rule

An activity is considered 50 percent complete when it begins and gets credit for the last 50 percent only when it is completed.

20/80 Rule

An activity is considered 20 percent complete when it begins and gets credit for the last 80 percent only when it is completed.


0/100 Rule

An activity does not get credit for partial completion; it only gets credit for full completion.


PMBOK P 185,


·          EAC forecast for ETC work considering both SPI and CPI factors. In this forecast, the ETC work will be performed at an efficiency rate that considers both the cost and schedule performance indices. It assumes both a negative cost performance to date, and a requirement to meet a firm schedule commitment by the project. This method is most useful when the project schedule is a factor impacting the ETC effort. Variations of this method weigh the CPI and SPI at different values (e.g., 80/20, 50/50, or some other ratio) according to the project manager's judgment. Equation: AC + [(BAC — EV) / (cumulative CPI x cumulative SPI)].




thanks SS pawar for a lucid explanation ..I hope everyone else also must have got the detailed reasoning

Pls keep up the spirit  and continue posting....