- Time Limit : stop after \(x\) seconds (or hours)
- Relative Gap: stop if gap between best possible bound and best found integer solution becomes less than \(x\%\). Different solvers use different definitions (especially regarding the denominator).
- Absolute Gap: similar to relative gap, but can be used when the relative gap cannot be computed (division by zero or small number).
- Node Limit: stop on number of explored branch & bound nodes.
- Iteration Limit: stop on number of Simplex iterations. This number can be huge.
If you specify several limits, typically a solver will stop as soon as it hits any one of the specified limits. In other words: multiple stopping criteria are combined in an "or" fashion.
stop if the time since the last new (and improving) integer solution exceeds a time limit