We are using Xpress Mp to solve a MIPS problem. After solving the model some times we see MIPStatus as SOLUTION and sometimes as OPTIMAL.What is the difference between them.What statuses can be considered as valid solution.

We are using Xpress Mp to solve a MIPS problem. After solving the model some times we see MIPStatus as SOLUTION and sometimes as OPTIMAL.What is the difference between them.What statuses can be considered as valid solution.

It often is a good idea to check for both status values. In both cases you will have a valid solution. The status XPRS_MIP_SOLUTION means that the search is incomplete (eg stopped by time limit), so the returned solution may not be optimal.