A missing ingredient. A value entered in the wrong unit. Two constraints that cannot be satisfied at the same time. In a complex feed formula, a small setup error can be surprisingly difficult to find.
Your formulation software may tell you that no feasible solution exists. But that only tells you there is a problem, not where the problem is.
For a simple formula, an experienced formulator may spot the cause quickly. In a multi-level recipe with sub-recipes and hundreds of constraints, troubleshooting can become a process of checking assumptions, changing constraints and recalculating until the source of the conflict finally appears.
That is where Extended Relaxation in BESTMIX® changes the process.
Imagine a formulator developing a new piglet feed. The formula contains minimum requirements for energy and amino acids, maximum inclusion rates for certain raw materials, fixed additives, production-related limits and ingredient restrictions.
The formulation software shows an error message ‘“The constraints cannot be satisfied”.
Where should the nutritionist start?
Is lysine impossible to reach because the available protein sources are restricted too tightly? Was a required premix accidentally left out? Is one ingredient fixed at such a high inclusion that there is not enough room for everything else? Or is there simply a data-entry error somewhere in the formulation?
Traditional troubleshooting can mean checking likely constraints, changing one, calculating again and gradually narrowing down the problem. Some formulation tools even recommend disabling nutrient constraints one by one until the problematic requirement can be identified.
In fact, a formulator might enter 10% when the intended value was 10 grams, use an incorrect nutrient value in the ingredient matrix, forget to make a required ingredient available, or introduce two limits that contradict each other.
A simple error can become a difficult search problem.
This is the problem Extended Relaxation in BESTMIX® is designed to address.
Extended Relaxation is not about automatically loosening constraints until BESTMIX finds something that works.
Its purpose is diagnostic.
When the original combination of requirements cannot produce a feasible solution, Extended Relaxation looks across the wider constraint set and produces a diagnostic suboptimal solution. It identifies the blocking constraints that had to be ignored to make that solution possible.
Suppose a particular requirement has been set at a minimum of 88, but under the other conditions in the formulation only 36 can actually be achieved.
Instead of leaving the nutritionist with “no feasible solution,” Extended Relaxation can point toward that requirement.
Now the investigation becomes much more focused:
Why can I only reach 36 when I need 88?
Perhaps the ingredient needed to supply it is missing. Perhaps another ingredient maximum is preventing enough of it from entering the formula. Perhaps the requirement was entered using the wrong unit. Or perhaps two otherwise reasonable constraints simply cannot coexist.
The software doesn't decide which requirement is wrong. It helps the formulator find where the conflict is.
Constraints are there for a reason. Nutritional requirements protect animal performance. Ingredient limits can reflect palatability, anti-nutritional factors or raw-material characteristics. Production constraints make sure a formula can actually be manufactured. Legal requirements are not negotiable.
Extended Relaxation is therefore not an invitation to remove constraints simply because they prevent a solution.
It is a way to answer a much more useful question:
Which part of this formulation should I investigate first?
For a simple formula, that can eliminate unnecessary trial and error. For a complex, multi-level formulation, it can prevent a nutritionist from searching through layers of ingredients, nutrients and constraints to find one incorrect value or conflicting requirement.
Optimization remains fundamental to feed formulation software. But there is another part of the formulator's job that deserves attention: diagnosis.
When a formulation fails, knowing that no feasible solution exists is only the beginning.
The useful questions come next:
Which requirements are blocking the solution? What could actually be achieved? And where should I start investigating?
That is the thinking behind Extended Relaxation in BESTMIX.
It doesn't replace the nutritionist's expertise or automatically decide which constraints should change. Instead, it gives the formulator a clearer path from “something is wrong” to “this is where I need to look.”
Because in complex formulation, finding the error can sometimes be harder than fixing it.
At EuroTier 2026, BESTMIX® is bringing eight capabilities that show how feed software is moving beyond traditional least-cost formulation, from uncovering the hidden cost of constraints and improving purchasing decisions to connecting formulation data with the wider business.
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