Differences between hard and soft constraints
If a hard constraint is violated, there is no solution. Breaking a soft constraint incurs a penalty of the value multiplied by the weights, which increases the objective function value.
| Constraints | Violation | Solution Space | Search Space | Solution Time | No solution risk |
|---|---|---|---|---|---|
| Hard | If a hard constraint is violated, there is no solution. | They decrease the solution space | They reduce the search space | Faster/Slower | There is a potential risk of no solution |
| Soft | Breaking a soft constraint incurs a penalty of the value multiplied by the weights, which increases the objective function value. | Same | Same | Slower | No risk |