estimate productivity in an Erlang project?

A rough rule of thumb is that about the same number of lines of code are produced per developer as in a C project. A reasonably complex problem involving distribution and fault tolerance will be roughly five times shorter in Erlang than in C. The traditional ways of slowing down projects, like adding armies of consultants halfway through, spending a year writing detailed design specifications before any code is written, rigidly following a waterfall model, spreading development across several countries and holding team meetings to decide on the colour of the serviettes used at lunch work just as well for Erlang as for other languages.  more