Notes on Cycles in Activity-on-Arc Networks

A new type of cyclic activity graph is introduced. In contrast to the well-known "start-after-end" type with only one backward arrow, the new one admits several backward arrows representing the removal of working groups from the n-th to the (n + 1)-th cycle (e.g., from the previous family house being constructed to the next one). It is shown how to calculate minimum cycle length, first and last possible starting times of activities and slacks. Brief examples of applications (e.g., in building industry, manufacturing of airplanes, ships and cranes) are mentioned. Moreover, an example of traffic signal settings is presented in detail.