Disjunctive constraint

From Glossary

Jump to: navigation, search

This is a global constraint enforcing the fact that two activities LaTeX: a_i and LaTeX: a_j requiring the same unary resource cannot overlap in time. Therefore, either LaTeX: a_i precedes LaTeX: a_j or LaTeX: a_j precedes LaTeX: a_i. In general the disjunctive constraint achieves arc_consistency on the formula: LaTeX: end(t_i)\leq start(t_j)  \vee end(t_j)\leq start(t_i) .

For discrete (cumulative) resource capacity, the disjunctive constraint holds when LaTeX: c_i +c_j > C where LaTeX: c_i is the capacity requirement of task LaTeX: a_i, LaTeX: c_j is the capacity requirement of task LaTeX: a_j and LaTeX: C the capacity of the resource.

See also the Cumulative_constraint.

Personal tools