Box Basic Cocomo Effort Formulas for Three Modes

1 05

Effort for Organic Mode: E = 2.4x (Size) Effort for Semidetached Mode: E = 3.0 x (Size]'12 Effort for Embedded Mode: E = 3.6 x (Size)'20

Table 11-2. Basic COCOMO Effort and Development Time Formulas

Mode

a

b

Effort Formula Effort = a x (Size)b

Development Time Formula

Organic

2.4

1.05

E = 2.4 x (S)1 05

TDEV = 2.5 x(E?'38 Months

Semidetached

3.0

1.12

1 12 E = 3.0 x (S)

TDEV = 2.5 x(E?'35 Months

Embedded

3.6

1.20

1 20 E = 3.6 x (S)

TDEV = 2.5 x(E?'32 Months

The same-size project yields different amounts of effort when it is considered to be of different modes: Suppose that a project was estimated to be 200 KLOC. Putting that data into the formula Effort = a x (Size)b

Effort for the organic mode would be estimated at 2.4 x (200) = 2.4(260.66) = 626 staff-months.

Effort for the semidetached mode would be estimated at 3.0 x (200)1 12 = 3.0(377.71) = 1,133 staff-months. Effort for the embedded mode would be estimated at 3.6 x (200)1 20 = 3.6(577) = 2,077 staff-months.

After effort is estimated, an exponential formula is also used to calculate a project duration, or completion time (time to develop, TDEV). Project duration is expressed in months.

Basic COCOMO Project Duration Estimation

Boehm devised three formulas (see Box 11?3) to be used for development time in the same fashion as he did with effort.

Project Management Made Easy

Project Management Made Easy

What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.

Get My Free Ebook


Post a comment