“…Morse suggested a procedure for deciding when duplicate copies are necessary based on R(t) and made a number of observations, for example that doubling the number of copies will not double circulation. If we restrict ourselves to consideration of the problems of loan and duplication policy only, then even up to the early 1990s were there analytical, statistical, stochastic, and simulation models galore [16] and since that time, with the advent of more powerful and cheaper computing, information, and decision support systems have made data more accessible and amenable to manipulation thus encouraging further quantitative analysis. The approaches adopted have been many and varied, often depending on the particular part of the system being modeled and a number of classic texts summarise the application of management science techniques to libraries [9,15].…”