Exercise 5.9Īpply the basic COCOMO model to the lines of code figures in Table 5.1 to generate estimated work-months of effort, assuming an organic mode. This reflected Boehm's finding that larger projects tended to be less productive than smaller ones because they needed more effort for management and co-ordination. means that larger projects are seen as requiring disproportionately moa* effort than smaller ones.

The exponent value k, when it is greater than I. Semi-detached mode - this combined elements of the organic and the embedded modes or had characteristics that came between the two.Embedded mode - this meant the product being developed had to operate within very light constraints and changes to the system were very costly.Organic mode - this would typically be the case when relatively small teams developed software in a highly familiar in-house environment and when the system being developed was small and the interface requirements were flexible.

These related to the technical nature of the system and the development environment. The constants, c and k (see Table 5.10), depended on whether the system could be classified, in Boehm's terms, as 'organic', 'semi-detached' or 'embedded'. The first step was to derive an estimate of the system size in terms of ktlsi. Where effort is measured in pm, or the number of 'person-months' consisting of units of 152 working hours, size is measured in kdsi, thousands of delivered source code instructions, and c and k are constants.

Generally, information systems were regarded as organic while real-time systems were embedded. the older version is now referred to as COCOMO 81.īoehm originally used mm (lor man-months) when he wrote Software Engineering Economics. The basic model was built around the equationīecause there is now a newer COCOMO II.

Of these only seven were business systems and so they could be used with applications other than information systems. The term COCOMO really refers to a group of models.īochm originally based his models in the late 1970s on a study of 63 projects. Boehm's COCOMO (Constructive COst MOdel) is often referred to in the literature on software project management, particularly in connection with software estimating.

Cocomo model cost estimation example