I guess I would like to see it become faster and more user-friendly.

I think CPLEX is very flexible for different languages so maybe they can provide more detailed documentation on how to format a model in CPLEX, and how to output the solutions. It could provide some examples, some specific standard examples, which I think would be very helpful for beginners.

I would also like to be able to receive feedback on why sometimes a problem gets solved easily and why sometimes it does not. If we had more insights into the problem structures we would know if we need to use the back end for some problems, or if we need to use other software or develop our own algorithms.

I would like see a more user-friendly interface, especially for new students. I would also like to have more options to choose from. Different problems have different options. We already have a different option in a CPLEX setting for the different search direction but I expect that we can combine with some heuristic matter, have that together.

For example, we might solve some stage at the beginning, find some infeasible and look at the bound. Then I can go to the feasible bound heuristic to find a good solution quickly.

I think one important feature to improve would be the speed of solving the problems. I know that CPLEX and other companies are trying to build new models, a new solution base to enhance the speed of solving problems. I think that is important. 

Also, it would be helpful if you had a more straightforward base to connect CPLEX to other software - to Java, to Python, and others. Make a platform so that it can be connected it to simulation software. That would be a plus.

One area in which I would like to see improvements made is in parallelization. Right now I can control the number of trials in which it can run, but maybe they can add more parallelization.

I'm pretty happy with the current release because I don't use a lot of fancy features of CPLEX. I use it just if I have to solve a linear program or I have to solve an integer problem.

There are some very rare cases when some integer programming problems are performed better by Gurobi compared to CPLEX, but it happens very rarely.

Maybe they already have it, but I would love to work with something with a direct GUI, instead of interfacing with Python. But my experience is only interfacing with Python.

It might already have it, but in the next release I would like to be able to use other languages, like Python or C, in calling CPLEX to solve the model. I think this would make it easier for the input data.

I would like to see something more for problems that are not linear. That is what I am looking for. Conic problems, and stuff like that. Though maybe CPLEX has it already and I haven't seen it.

The infeasibility checks should be easier to set up. Currently, you have to name your constraints. It is really hard to find the infeasible constraints. If they could add that to the features, it would be great. 

It would also be awesome if they had a short tutorial that tells someone like me, who is not a new user, about the different features that I might not be aware of. Sometimes I will talk to a friend who will tell me that they are using a CPLEX feature that I didn't even know existed. I know what the software does but it would be helpful to have a tutorial that summarizes all of the features.

It is also a problem that CPLEX does not have a user-interface in Mac.

One of the new things in CPLEX is the new benders, the composition that does it automatically. One of the things I realized while testing it is that when it does it at the root node of the branch and bound tree, it doesn't leave with the LP relaxation. It often stops, terminates, before it stops adding cuts before. And it makes for a very weak stopping criteria later on in the branch and cut tree. So maybe polish it a little more. I know it is a very generic framework, but I think just by doing that one thing, it could really improve its performance for a lot of stuff. 

What I'm looking for is actually nonlinear programming. I don't think CPLEX has that. There are some nonlinear program solvers in open source but they don't work well. So if some major commercial solver corporation has that option, it could be very useful.

Actually, when CPLEX adds something it becomes more difficult for me to publish a paper. Maybe CPLEX can sleep a little bit and not make any improvements for a while.

In future versions, I would like to see them include different kinds of optimization problem techniques. The performance could also be faster.

One more thing that I would like to see added is the ability to find out how much time other solvers take. I know that CPLEX is one of the solvers, but it would be very helpful to be able to figure out what I need in order to optimize my quota in the runtime of a particular problem.

What I would love to see is better accessibility of the engine extensions. Currently you can do really low-level stuff, and it's great, but you can only do it in C or C++. Whereas, sometimes the application requires another programming language, like Java or Python, and then you simply can't reach the engine extensions from either the Java or Python interface, and that is really a pity.

It would be really nice if you could write your extension in C++ but edit, or use it, through Java. That would be an improvement. But just being able to do everything completely from Java or Python would be a major improvement, and is probably something that CPLEX's competitors already have. So that is something I would really love to see in CPLEX too.

I am also involved in the open-source community and CPLEX is, unfortunately, not particularly nice because it is very expensive to buy. And I understand that obviously you need to earn money with CPLEX, so charging corporate members is necessary. But it would be nice if academics and people in the open-source community could also have access to it, or to a limited version of CPLEX.   

The layout of the program, the way the windows appear. It's kind of confusing at the beginning to get a hold on.

I would like for them to offer a free version. We have to use the version that we got from my teacher but sometimes it doesn't work. 

I would also like for there to be more tutorials explaining how to improve solutions. Sometimes I do not know how to improve my solution, so I need a tutorial for that.