Q. Explain Equivalent size measure software metrics?

Equivalent size measure:- Models makes no distinction between a new software and the portion being reused. The equivalent size measure Se, is a function of Sn (new developed code) and Su (reused code); means that the efforts required to develop the software with Sn and Su is equivalent to the effort of developing a product with Se "from scratch". Sometimes there may be an undesirable situation in which it actually costs more to put together several existing program segments then it would to construct equivalent software from scratch.

Boehm has proposed a function for equivalent size measure as

Se=Sn+(a/100)Su

Where the adjustment factor 'a' is determined by the percentage of modification required of design(DM), of the code(CM), and of the efforts necessary for the integration of the modified code(IM).