The paper describes the work done on modelling and simulation of a mul
tistage flash desalination plant containing 15 recovery and 3 rejectio
n stages. Both the steady-state and dynamic simulations have been carr
ied out through the use of SPEEDUP package. In addition, a specificall
y written FORTRAN program is used for the steady-state simulation base
d on tridiagonal matrix formulation. Good agreement is achieved by com
paring with the vendor supplied as well as actual plant data.