IBM ILOG CPLEX Optimization Studio Reviews

I used CPLEX to solve a linear programming problem, where there was a compartment and there were a lot of containers in that compartment, and I had to optimize the space in that compartment to fit in different size containers. 

I am a data science guy and I'm doing optimization, so CPLEX  helps me when I am not able to solve a problem using machine learning data science principles, and I can solve it using CPLEX. CPLEX is a tool that offers something which cannot be done by statistics or machine learning tools. 

The performance was good, but I can't compare it with any other tools, because this is the only tool that I have used.

I really like that I can see the results properly. I can click on the results and then look at them to tell how the results are coming out.

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.

I have not experienced any issues with stability but I have heard from my friends that there are other tools which can perform better than CPLEX sometimes, in terms of computation. 

CPLEX is limited to the linear programming and mixed integer programming. It is not extended to nonlinear programming, so I think the scalability can be an issue in that area. Though, most of the programs in the current industry are having linear programming problems, so I think CPLEX has a good future.

CPLEX was the first optimization tool that I have used. I started using CPLEX when a supervisor in my previous company told me to try it out.

The initial setup was straightforward. I did not face any issues with the installation.

When selecting a vendor I would check if the performance is faster, the results are more accurate, and the GUI is more user-friendly than the competition.

I might recommend CPLEX to a colleague, depending on the problems that they are working on. If a university is seeking challenging problems in an area which is heuristic optimization or non-linear optimization, I do not think that CPLEX is the best software to do that. 

In terms of linear programming, CPLEX should be the first choice.

I just use it for solving mixed integer program models.

It performs well, depending on the problem structure. Some problems have a lot less structure so they can be solved very fast, even when they are very large scale problems. But it's tricky. I don't know why, but sometimes it works very fast and other times I cannot solve it in a reasonable amount of time.

It helps me a lot. CPLEX is a tool that can kind of visualize your prediction and help you understand the problem better. For example, for every SOS you can just format a model, which could be an inner model or mixed integer model, that can be solved by CPLEX. You can then see the results to verify your idea, or you can modify your idea.

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.

For some types of problems the performance is stable. There are other algorithms, like MetaRisk and generic algorithms, that perform much worse than CPLEX. Though if I were able to get some insights as to what type of problems perform best on CPLEX I would be able to use it more efficiently.

When I was an undergrad I used Nengo but I heard about CPLEX from my teacher in university, as well as from from friends who recommended it. I also used Gurobi. 

The installation was straightforward. 

If I had a colleague who was considering CPLEX I would tell them to just use it. It is very well-known and has a good reputation. So when you have a model that you solve with CPLEX, other people will be more convinced by your results. 

I'm a professor in optimization. I do a lot of VIC routing scheduling problems and for those particular cases I use CPLEX and CP Optimizer a lot.

It performs really well. Sometimes you find bugs in there but the support team is good at getting them fixed.

I would say its extensibility, and the ability to do both high-level modeling and also go all the way to the engine extensions.

Whenever you do optimization, having a good CP solver or integer programming solver is a necessity. So CPLEX is a tool that I cannot do without.

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 stability is reasonably good. Every single version has some bug, which I somehow always encounter. Some of these issues are really severe and literally crash the engine. Very rarely, I find issues which actually impact the accuracy of the results. That has happened twice so far. In general, it is okay.

I find scalability to be more of an issue that comes from the modeling. If it doesn't scale, then it is usually the problem of the modeler. Some problems are just too big to give as a whole piece to solve and expect a reasonable answer in a reasonable amount of time.

I do not use technical support because that is for enterprise users but as an academic I do have direct connections to the development team. I find that the support from the development team is superb. I have frequently interacted with people from the team and they usually fix my bug within the next version. Sometimes I get access to an early developer version if it is a really crucial issue.

I used to frequently interact on the IBM website but it was a major pain. It is absolutely a garbage website. It takes effort to find, the form is really bad, the markup is really bad - they should just switch to any other platform and make it searchable. There is a search function but it is really bad. 

I download my software through the academic initiative, and obviously I love the initiative, but finding the initiative is an absolutely horrible experience too. Every year or so, there is a new version of CPLEX or CP Optimizer and I think, "Oh that's great, I would love to upgrade." Then I need to search, I actually need to search on Google, to find the link to the academic catalogs and then download it. It is really a painful experience. Try finding anything on the IBM website, and that doesn't work either. So the website is one of the major problems at the moment. 

I started using CPLEX because I needed access to an integer programming solver and the CP solver. I wasn't using another product beforehand.

The instillation is super easy. You just download it and run the executable in either Linux or Windows, and three questions later it is done. 

The only thing that is hard is if you connect directly to CPLEX through Java you will have to deal with classpath information and linking, which is not explained well. I frequently see people asking questions on websites like Stack Overflow or on the IBM forms about how to do this. CP is significantly easier, but it is still hard.

When researching a product I consider what the quality, the support, and the documentation are like. The documentation for CPLEX, specifically the accessibility and where to find the documentation, is something that should be majorly improved.

If you are interested in CPLEX I recommend that after you install it, look over the examples that you get. There are some old, very hidden tutorials on how to do this. At some point, somebody from IBM wrote a manual on how to do scheduling in CP. That manual was very hard to find but if you can find it, it is a very valuable source of information.

I use it for building mathematical optimization models for scheduling and assignment kind of models.

It has performed very well.

Definitely the speed of the response time. But, I get to also play a lot of variables, also configuration parameters, which CPLEX uses. I think these two features are important. 

A third feature that I find to  be very valuable is the Concert library. I am used to using CPLEX with the old fashioned C++ library, where I have very easily integrated with the C++ framework. I can now also use this Concert library in the same way that I can use the CP, Constant Propagation, as well as CPLEX, which is the optimization. So, having both of the technologies in the same library is a very important feature to me, maybe the most important feature.

I have used it to solve models for our clients, so all the usual mathematical optimization; the benefits it has given me is in terms of business.

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.

The stability is good.

I sometimes have an issue with the scalability but until now it has been reasonable. 

We use CPLEX because it is the industry standard. Before CPLEX I used open source software and LINDO. 

As a consultant, I need to consider various factors such as cost, performance and client preferences. Taking in these factors, I decided to go with CPLEX. It is the best.

The instillation was pretty straightforward. 

I would definitely recommend CPLEX to my colleagues.

I use CPLEX to solve integer programming formulations. I think the performance is good. We can use it solve many problems, and it did. 

I think we can code quickly. I used C++ before, it would take me a long time to code in the platform. But I can really code in CPLEX easily, and I can solve problems quickly.

It's easy to read, it's easy to code.

Not me, but my group members published high-quality papers relying on CPLEX.

We really use CPLEX to get the exact optimal solutions. But for other algorithms, we can just get approximately optimal results.

Compared with C++, which I used before, for larger transportation networks, CPLEX will take a longer time. For the shorter ones, it's very quick.

I didn't use tech support.

I think it is easy to do.

If I had a friend at another university and they had the same problem as me or a similar formulation as me, just integer programming, if CPLEX can be used to solve those problems, I would introduce CPLEX to them.

My primary use case was for a class that I've taken in integer programming where it required us to implement some basic models in CPLEX. It performed really well. It was a little bit difficult to get at the beginning. What was difficult was setting the sets into it, sets of variables.

The best thing is that it offers, compared to other programs that I've used - LINDO and LINGO - it gives you much control on the parameters and the sets, so you can do a lot more with CPLEX.

It helped me because it was just easier to implement complex models. That's it. But if it was a basic model, then I would use another program. It's not worth the complexity.

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

Great. It never crashed. No lag time.

I didn't implement any complex models in it, but I feel if I were to do that, I would use CPLEX for sure.

I didn't use it, except at the beginning. Licensing stuff. That was OK.

LINDO and LINGO.

I wasn't involved in setting it up.

From my experience, it's the best out there for complex models.

This is for research, I try to develop some optimization models. I solve the problem, I write in Python, and then interface with the CPLEX package. The performance has been pretty good. I think the speed is pretty fast, although I think the interface with Python is not as friendly, because the way that you put in the data is not that intuitive.

Usually it solves problems really fast, so that's what's most important to me.

It definitely helps because it's a solver, I can just plug in and use. It's a tool that I have to use, basically.

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.

I think it's pretty stable.

I haven't tried really, really big problems, so for your everyday problem it's fine.

But I did have some problems with error messages where, for example, it's infeasible, but instead of telling you it's infeasible it will give you something else.

I haven't used it.

I also use Gurobi sometimes. I think the university picked CPLEX just because we have a license.

I wasn't involved. It's all set up on the school server, so I just call it.

Learn how to use languages that interface with CPLEX, because then you can get very customized.

To solve LPN-IP. Performance was pretty good. I had some problems with solving one problem, but the problem was because of my formulation. Once I added it, it worked very well.

I have experience in Xpress and Gurobi, also. It is easy to write a code in CPLEX. That's a valuable thing.

What I'm doing is finding some clusters in a network. I'll build a model and apply  it to CPLEX and find some clusters. I can interpret some useful meanings about that.

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.

Stability is fine. It's reasonable. Most of the problems are getting slower if I increase the number of nodes or something, but it's a typical thing.

I haven't used it.

Xpress and Gurobi. I'm not switching. It depends on the project. I can use all of them.

I wasn't involved. Not in upgrades either. There is just  one size installed. I use it every time.

I think CPLEX is the most familiar, other than Xpress and Gurobi. So, it is easy to recommend to others for general use. If they want some specific options or something then, I have to look for a manual.

I design algorithms to solve transportation problems and then I often use CPLEX as an engine within those algorithms to solve optimization problems.

It has performed very well. I have been using it since 2007 and it has gotten much better over time.

The way you can interface with it from a programming perspective, the implementation, is very useful. And, just generally, its performance. 

CPLEX is fairly easy to use and it does provide very high quality solutions which make my algorithms run faster and better.

I have not had any issues with stability.

The algorithms that I design are based on the premise that CPLEX struggles when there is a lot of data. So CPLEX on its own won't scale to the size of problems that I am trying to solve, though I kind of like this because it gives me something to do. But it seems that it can solve bigger and bigger problems every year.

CPLEX is sort of what I learned on. I will admit that I have used other products too, but CPLEX is what I know the best.

I have installed it on my own computer and it was easy.

It is still not clear to me what the GPU potential is for CPLEX. Can you leverage GPU technology, essentially? I think that would be interesting given how many processors there seem to be in those types of machines.

As an academic, when I am selecting a vendor, the first question that I ask is, "is it free"?  That plays a big role. But a product's reputation, the recognition of the brand name when I publish my results, that makes a difference too. I want to be able to say that I used a solver that everyone knows and respects. People will say, "Oh, yeah, of course he uses that. He did that the right way." 

If I were to offer advice to colleagues considering CPLEX I would tell them there is a learning curve, but that it is worth doing. That you will really see a benefit from putting the time in.

I use CPLEX mainly for validation of the algorithms that I develop, such as metaheuristics. I want to compare their performance against CPLEX.

I also use it to validate my models. The math models that I make, mixed-integer programming and stochastic programming. In order to make sure that they are feasible, to test them, I use CPLEX. And if there is a case study that is small, I usually use CPLEX to solve it.

The performance is good for those exact solutions. But, in general, exact methods have this problem of computation time. And the amount of memory they need is considerable, sometimes. It also takes a while to learn how to adjust the settings of the software so it can perform better.

I think that it is user-friendly, compared to other methods. 

I also like the optimization studio in Windows. It is really awesome for someone who wants to just start using CPLEX, especially the OPL for writing the model. The language is really, really simple and intuitive and it is very easy to read and write. it's also easy to write control flows in CPLEX.

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.

You need to learn how to play with the settings so it doesn't crash. But if you run on the default settings and your program size is large, it might crash after about an hour.

I have never personally contacted to ask for support. I usually just google the problems that I have. There is usually a forum where I can find the answer.

Beforehand, I was using GAMS for my masters degree. Then my advisor recommended using CPLEX. Once I installed it I found that I loved the OPL and how easy it was to write down the model. So if I want to do something really quickly, I go straight to CPLEX's studio and write it there. 

I also use Gurobi, in conjunction with Python. This is just because one of my course instructors used Gurobi with Python. But it shouldn't be any different, it's the same. 

I had installed Optimization Studio. That was very easy and straightforward. The other one, for Mac, that one was a little tricky. I had to search online for instructions for the installation.

I would definitely recommend CPLEX to colleagues who are thinking of using it. It is very reliable and there is a lot of programming behind it. I am confident that I can rely on the solutions that it gives me.