Allow plenty of time for large-scale software

Estimation of development time for multimillion-line software is addressed. Three methods are discussed. The historical-database approach finds the statistical trend line by regression analysis that relates project development time to size in source lines, and extends it to a ten-million-line size. The software macroestimation methods, Cocomo (cost constructive model) and the software life-cycle model, forecast labor effort and schedule from early estimates of the amount of functionality in the project. The three methods all point to the conclusion that a large amount of time must be allowed.<>