St. Dismas Chapter 7 Questions

25. A project in its 26th week has an actual cost of $270,000. It was scheduled to have spent $261,000. For the work performed to date, the budgeted value is $272,000. What are the cost and sched¬ule variances for the project? What are the SPI and CPI?
Actual cost =$270,000
Earned value = $272,000
Planned cost = $261,000
Cost variance = $272,000–$270,000= $2,000
Schedule variance = $272,000–$261,000= $11,000
SPI = $272,000/$261,000 = 1.042
CPI = $272,000/$270,000 = 1.007

26. A project has just completed the 87th item in its action plan. It was scheduled to have spent $168,000 at this point in the plan, but has actually spent only $156,000. The foreman estimates that the value of the work actually finished is about $162,000. What are the spending and schedule variances for the project? What are the SPI and CPI?
Actual cost =$156,000
Earned value = $162,000
Planned cost = $168,000
Cost variance = $162,000–$156,000 = $6,000
Schedule variance = $162,000–$168,000 = - $6,000
CPI = $162,000/$156,000 = 1.038
SPI = $162,000/$168,000 = 0.964

27. The following project is at the end of its sixth week. Find the cost and schedule variances. Also find the CPI and SPI. Then find the critical ratio of the project using earned value calculations. Finally, calculate the ETC and EAC for the project.

Activity Predecessors Duration(weeks) Budget $ Actual Cost $ % Complete a 2 300 400 100 b 3 200 180 100 c a 2 250 300 100 d a 5 600 400 20 e b,c 4 400 200 20

Actual cost =$400+$180+$300+$400+$200=$1,480
Earned cost=$300+$200+$250+.2($600)+.2($400)=$950
Planned cost=$300+$200+$250+.8($600)+.8($400)=$1,550
Spending variance=$950-$1,480=-$530
Schedule variance=$950-$1,550=-$600
SPI=$950/$1,550=0.6129
CPI=$950/$1,480=0.64189
CR=($950/$1,550)($950/$1,480)=0.393
BAC=$300+$200+$250+$600+$400=$1,750
ETC=($1,750-$950)/0.64189=$1,246.32