The Scientific World Journal

Research Article

A Graph-Based Ant Colony Optimization Approach for Process Planning

Precedence relationship between features and operations.


Features	Operation	Precedence constraints description

F1	Milling (Op₁)	F1 (Op₁) is the datum face for the part; hence, it is machined before all features

F2	Milling (Op₂)	F2 (Op₂) is before F10 (Op₁₂, Op₁₃, Op₁₄) and F11 (Op₁₅, Op₁₆) for Rule 2

F3	Milling (Op₃)

F4	Drilling (Op₄)

F5	Milling (Op₅)	F5 (Op₅) is before F4 (Op₄) and F7 (Op₇) for Rule 4

F6	Milling (Op₆)	F6 (Op₆) is before F10 (Op₁₂, Op₁₃, Op₁₄) for Rule 4

F7	Milling (Op₇)	F7 (Op₇) is before F8 (Op₈, Op₉, Op₁₀) for Rule 4

F8	Drilling (Op₈)
	Reaming (Op₉)	Op₈ is before (Op₉ and Op₁₀); Op₉ is before Op₁₀ for Rule 3
	Boring (Op₁₀)

F9	Milling (Op₁₁)	F9 (Op₁₁) is before F10 (Op₁₂, Op₁₃, Op₁₄) for Rule 4

F10	Drilling (Op₁₂)	Op₁₂ is before Op₁₃ and Op₁₄; Op₁₃ is before Op₁₄ for Rule 3; F10 (Op₁₂, Op₁₃, Op₁₄) is before F11 (Op₁₅, Op₁₆) for Rule 4 ;Op₁₂ of F10 is before F14 (Op₁₉, Op₂₀)
	Reaming (Op₁₃)
	Boring (Op₁₄)

F11	Drilling (Op₁₅)	Op₁₅ is before Op₁₆ for Rule 3
	Tapping (Op₁₆)

F12	Milling (Op₁₇)

F13	Milling (Op₁₈)	F13 (Op₁₈) is before Op₄ and Op₁₇ for Rule 2 and Rule 1, respectively

F14	Reaming (Op₁₉)	Op₁₉ is before Op₂₀ for Rule 3
	Boring (Op₂₀)