A Graph-Based Ant Colony Optimization Approach for Process Planning

Table 2

Precedence constraints between operations.

Features	Operations	Precedence constraints description
F1	Op1	Op1 is prior to Op2 and Op3 for Rule 2.; Op1 is prior to Op4 and Op5 for Rule 5.
F2	Op2	Op2 is prior to Op3 for Rule 3.
F3	Op4	Op4 is prior to Op5 for Rule 3.
	Op4, Op5	Op4 and Op5 are prior to Op6 for Rule 5.; Op4 and Op5 are prior to Op7 for Rule 5.
F4	Op6	Op6 is prior to Op2 and Op3 for Rule 4.
F6	Op8	Op8 is prior to Op9 for Rule 3.
	Op8, Op9	Op8 and Op8 are prior to Op7 for Rule 5.