The paper considers an N-period planning horizon with known demands Dt, ordering cost At, procurement cost, Ct and holding cost Ht in period t. The dynamic lot-sizing problem is one of scheduling procurement Qt in each period in order to meet demand and minimize cost. The Wagner-Whitin algorithm for dynamic lot sizing has often been misunderstood as requiring inordinate computational time and storage requirements. The paper presents an efficient computer implementation of the algorithm which requires low core storage, thus enabling it to be potentially useful on microcomputers. A FORTRAN implementation on an Amdahl 470 yielded computation times (in 10’-3 seconds) of T=¸-0.249+0.0239N+0.00446N2. Problems with N=100 were solved in under two seconds.
