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Making Dreams Come True (Or Not)
Last week, in my What Is The Solution When There Is No Solution entry, I commented about the fact that not all business requirements were actual constraints and that some of these are probably wishes that business people dream to fulfill. Making the difference between wishes and hard constraints is key to success. Indeed, handling wishes as hard constraints may result in infeasible models, which would be useless to the business people that come to you for help. It turns out that there is a surprisingly simple way to detect that some... [More]
Tags: optimization modeling analytics 
When Better Is Not Better
I don't know about you, but my experience is that all customers want the best solution to their business problem. And they want it rapidly, within some given time limit. I can't blame them, I do the same when I am the customer. However, if we have finite computing resources then there is a limit to what can be computed. If the business problem is so complex that it can't be solved exactly in the given time limit, then optimization won't compute the best possible solution (one among the optimal ones). What it will compute are good feasible... [More]
Tags: analytics optimization cplex 
Interesting Optimization Blogs
Mathematical optimization is often called Operations Research (OR). I'll keep using mathematical optimization, or optimization in short, here, but if you want to learn more about it look for OR resources, for instance OR blogs. The good news here is that Mike Trick is maintaining a list of interesting blogs on his home page: http://mat.tepper.cmu.edu/blog/ Look for the right column, and you'll find a very interesting list. I won't reproduce it here, but all are worth a look at. It is truly a great list. Note that I am not saying this... [More]
Tags: blogs optimization learning 
Nice Graphics Always Win
I remember the first demo I made. It was last century, in 1990 if I remember well. No, I wasn't using punch cards. Believe it or not, but at that time there were computers with a mouse, a windowing system, decent programming languages, and a good OS called Unix. Yes, this old fashioned ancestor of Linux and Mac OS X. Even Internet existed back in those old days... Anyway, here was I, so proud that my solver was able to solve the zebra puzzle . The demo went as follows. I press... [More]
Tags: analytics optimization predictive 
Is Optimization Really Part Of Analytics?
I looked at this question not so long ago but it is worth revisiting using the new analytics definition proposed by INFORMS . The proposed definition reads: "Analytics  the scientific process of transforming data into insight for making better decisions." I like it. It is concise, well worded. Optimization seems covered by the "making better decisions" part. However, the new definition seems very (too
much?) data centric as stated by Ehsan Nikbakhsh on Or Exchange . Indeed, it clearly base decision making on... [More]
Tags: analytics optimization informs 
Issues Are Not Where One Think They Are
Where are the issues when one tries to use optimization to improve business? They may not lie where one think. My former colleague Laurent Perron (now at Google) splits the average time spent on optimization projects as follow in his CP 2011 invited talk : 50% Getting the right problem with the right people 25% Getting clean data 5% Solving the problem 20% Reporting the results/Explaining the implications One could argue about the exact split, but the broad picture is true as far as I can tell from my experience. I would... [More]
Tags: graphics analytics optimization 
Simulation And Optimization Are Not The Same
Selling optimization to happy users of simulation technology can be a tough nut to crack. Here is an example I find quite effective at opening eyes. Before diving into it let me start with a disclaimer. I am not trying to show that optimization is superior to simulation, nor am I trying to undermine the value of simulation. I simply want to make clear that simulation and optimization are two different things, each with its own value. There are cases where optimization is a better fit, as shown below. There are also cases where simulation... [More]
Tags: analytics simulation optimization 
It Is Too Slow
"It is taking too long". Who didn't heard it at least once? I mean, who among those who thought they had successfully solved a challenging optimization problem? This came again during a discussion with colleagues of mine in IBM consulting arm last week. They have an unhappy customer. This happens, why blog about it? Well, the reason why the customer team is unhappy is worth telling. They are unhappy because they cannot scale the optimization solution. They can successfully solve a problem with 10,000 items (that was the... [More]

What Is The Gap?
My last blog entry triggered a discussion on twitter, where one said customers should not wait hours to get their problem solved. This made me think and I decided not to answer directly. Why? Because such discussion is meaningless until we agree on what "solving" means. Let's go back to the basics. Excuse me if I sound pedantic, but I had to go through the same explanation when I learned about mathematical programming (MP). Indeed, my background was in constraint programming (nobody is perfect) and learning MP was kind of... [More]
Tags: optimality optimization 
Looking Under The Hood
Go to market (GTM) is something you must understand very quickly if you try to live from selling what you do. For optimization, we converged on a very simple view at IBM. There are two categories of customers, those who understand the technology, and those who don't. The formers are operations research (OR) practitioners and OR academics. The latter are line of business (LOB) people. Understanding how the technology work is not so much important to them. What is important is to understand what it enables. The OR market is well served by... [More]
Tags: optimization modeling 