Activity networks and precedence tablesEdexcel A-Level Further Maths: Mind map

Exam questions on Activity networks and precedence tables

1. A project has activities P, Q, R, S and T. The immediate predecessors are: P none; Q none; R is P; S is P and Q; T is R and S. The project is to be modelled by an activity network with the activities on the arcs.
   Explain why a dummy activity is needed in this network.2 marks
2. A project is modelled by an activity network with events numbered 1 to 6. The activities, with their start and end events, are: A (1 to 2), B (1 to 3), C (2 to 4), D (3 to 4), E (4 to 5), F (3 to 5) and G (5 to 6). There is also a dummy activity from event 2 to event 3.
   State the immediate predecessors of activity E and of activity F.2 marks
3. A project has activities A, B, C, D and E. The immediate predecessors are: A none; B none; C is A and B; D is B; E is C and D. The project is to be modelled by an activity network with the activities on the arcs.
   Explain why one dummy activity is needed, and state where it must be placed.3 marks