DESIGN FOR SIX SIGMA (DFSS) TEAM AND TEAM SOFTWARE PROCESS (TSP) - Software Design for Six-Sigma: A Roadmap for Excellence - page 279

Step Activities Description

4B Size Estimating

Procedure 4B

- Using the linear-regression method, calculate the β 0 and
β 1 parameters from the plan added and modified size and
actual added and modified size data.
- If the absolute value of β 0 is not near 0 (less than about
25% of the expected size of the new program), or β 1 is not
near 1.0 (between about 0.5 and 2.0), use procedure 4C.

4C Size Estimating

Procedure 4C

If you have any data on plan added and modified size and
actual added and modified size, set β 0 = 0and β 1 =
(actual total added and modified size to date/plan total
added and modified size to date).

4D Size Estimating

Procedure 4D

If you have no historical data, use your judgment to
estimate added and modified size.

5 Time Estimating

Procedure

- If you have sufficient estimated proxy size and actual
development time data (three or more points that
correlate), use procedure 5A.
- If you do not have sufficient estimated size data but have
sufficient plan added and modified size and actual
development time data (three or more points that
correlate), use procedure 5B.
- If you have insufficient data or they do not correlate, use
procedure 5C.
- If you have no historical data, use procedure 5D.

5A Time Estimating

Procedure 5A

- Using the linear-regression method, calculate the β 0 and
β 1 parameters from the estimated proxy size and actual
total development time data.
-If β 0 is not near 0 (substantially smaller than the expected
development time for the new program), or β 1 is not
within 50% of 1/(historical productivity), use procedure
5B.

5B Time Estimating

Procedure 5B

- Using the linear-regression method, calculate the β 0 and
β 1 regression parameters from the plan added and
modified size and actual total development time data.
-If β 0 is not near 0 (substantially smaller than the expected
development time for the new program), or β 1 is not
within 50% of 1/(historical productivity), use procedure
5C.

5C Time Estimating

Procedure 5C

- If you have data on estimated-added and modified size
and actual development time, set β 0 = 0and β 1 = (actual
total development time to date/estimated-total added and
modified size to date).
- If you have data on plan-added and modified size and
actual development time, set

β 0 = β 1 =

(actual total
development time to date/plan total added and modified
size to date).
- If you only have actual time and size data, set

0and

β 0 = 0and

β 1 = (actual total development time to date/actual total

added and modified size to date).