1-click to solve the linear programming problem after change each modified cell, using vba for backend work, will keep flexibility to identify all the conditions (if more than 20 cells in future, will still work without changing the code or excel file). And this is my first project bid on Freelancer, may not have any reputation but I'll do my best to gain the reputation by doing your project. BTW, I've completed a similar project in my company by building LP model in excel to optimize production line schedule. :)