
The 5th edition of Model Building in Mathematical Programming discusses the general principles of model building in mathematical programming and demonstrates how they can be applied by using several simplified but practical problems from widely different contexts. Suggested formulations and solutions are given together with some computational experience to give the reader a feel for the computational difficulty of solving that particular type of model. Furthermore, this book illustrates the scope and limitations of mathematical programming, and shows how it can be applied
Model Building in Mathematical Programming by H. Paul Williams (5th Edition)https://www.wiley.com/en-us/Model+Building+in+Mathematical+P...
if your problems can be attacked by LP / MIP type stuff, there's a book "model building in mathematical programming" by Williams that has a couple dozen different optimisation problems for a range of applications, with worked examples of how to formulate a model to solve each of them. each problem will be much less complex than your real-world optimisation puzzle but if you browse through the problem descriptions you might be able to match some against parts of your situation & get ideas for how Williams would model and optimise it.
As an example, a particularly prestigious problem to work on there was optimization of order fulfillment across warehouses with different inventory to reduce costs for split shipments (order two things and get two boxes? That's a split shipment). It's a very difficult problem to solve, considering that there is optimization within an order but also across different orders from the same customer that are yet unfulfilled, and even across completely unrelated orders competing for the same inventory. And with hundreds of thousands of fulfillment options for even a two unit order, it can get extremely complex very quickly. That problem, by the way, is one that was worked on by a founder of instacart when he was still at Amazon.
If you're really interested in IP/LP/MILP/CP with business applications, start picking up literature within the Operations Research discipline. There are plenty of great books to go around. I'd recommend Model Building in Mathematical Programming...its mostly an intro to LP techniques, but the it was the book that made things click for me in terms of identifying and translating real world problems into mathematical models.