Question

A project consists of six tasks. Task A is scheduled to begin at the start of week 1 and finish at the end of week 4. Task B is scheduled to begin at the start of week I and finish at the end of week 2. Task C is scheduled to begin at the start of week 3 and finish at the end of week 4. Task D is scheduled to begin at the start of week 1 and finish at the end of week 1. Task E is scheduled to begin at the start of week 2 and finish at the end of week 4. Task F is scheduled to begin at the start of week 4 and finish at the end of week 4. The budgeted cost for task A is $10,000, for task B is $2,000, for task C is $3,000, for task D is $1,000, for task E is $6,000, for task F is $4,000. At the end of the third week task A is 80% complete, task B is 100% complete, task C is 40% complete, task D is 100% complete, task E is 55% complete, and task F has not started.

1aWhat is the schedule performance index for the project at the end of the third week?

Answer 1

To find the Schedule Performance Index (SPI) at the end of the third week, first calculate the Earned Value (EV) for each task, then compute the Planned Value (PV), and finally divide EV by PV. The SPI is 1.033, indicating the project is slightly ahead of schedule.

Step-by-step explanation:

To calculate the Schedule Performance Index (SPI), we need to understand the concept of Earned Value Management (EVM). The SPI is a measure of schedule efficiency and is calculated by comparing the work performed by the end of a certain period to the work that was scheduled to be performed by that same point in time.

The formula for SPI is:

SPI = (Earned Value) / (Planned Value)

First, we calculate the Earned Value (EV) for each task by multiplying the budgeted cost with the percentage of completion:

• Task A: $10,000 x 80% = $8,000
• Task B: $2,000 x 100% = $2,000
• Task C: $3,000 x 40% = $1,200
• Task D: $1,000 x 100% = $1,000
• Task E: $6,000 x 55% = $3,300
• Task F: $4,000 x 0% = $0

Total EV = $8,000 + $2,000 + $1,200 + $1,000 + $3,300 + $0 = $15,500

Next, we compute the Planned Value (PV) for each task, which is how much the work was budgeted to cost by the end of the third week. Only tasks scheduled to work during this time have PV:

• Task A: Should be 75% complete, so $10,000 x 75% = $7,500
• Task B: Should be 100% complete, so $2,000 x 100% = $2,000
• Task C: Scheduled to start at week 3, should be 50% complete, so $3,000 x 50% = $1,500
• Task D: Should be 100% complete, so $1,000 x 100% = $1,000
• Task E: Should be 50% complete, so $6,000 x 50% = $3,000
• Task F: Not scheduled to start until week 4, so $4,000 x 0% = $0

Total PV = $7,500 + $2,000 + $1,500 + $1,000 + $3,000 + $0 = $15,000

We can now calculate the SPI:

SPI = EV / PV = $15,500 / $15,000 = 1.033

The Schedule Performance Index of above 1 indicates the project is ahead of schedule.