A furniture manufacturer makes ₦20,000 per shelf, yet I recommend producing zero of them.

Why would you deliberately stop producing a product that makes money?

Because a product can be profitable on its own and still be the wrong use of your scarce resources.

The business

Suppose a small furniture manufacturer is planning production for one month.

It has:

• 400 units of wood

• 100 machine-hours

• 160 labour-hours

It produces three products:

There are also limits to how much the business expects to sell during the month:

• Maximum 40 tables

• Maximum 100 chairs

• Maximum 60 shelves

So the question isn't:

“Which product makes the most money?”

It's:

“Given the resources available, what combination of products produces the highest total contribution?”

The result

I analysed the production decision while accounting for the available wood, machine time, labour and expected demand.

The recommended production mix was:

Total contribution:

₦1.3 million

And yes:

Zero shelves.

But why?

The answer is opportunity cost.

The resources used to manufacture a product have value because those same resources could potentially be used elsewhere.

In this particular production plan, an additional machine-hour is worth approximately ₦5,000 in contribution.

An additional labour-hour is also worth approximately ₦5,000.

A shelf requires:

• 2 machine-hours

• 3 labour-hours

So the opportunity cost of the resources required to produce one shelf is approximately:

(2 × ₦5,000) + (3 × ₦5,000)

= ₦25,000

But the shelf contributes only:

₦20,000

So producing that shelf would consume resources that could generate approximately ₦25,000 elsewhere, while the shelf itself contributes only ₦20,000.

The difference is:

₦5,000

That's why the recommendation is zero shelves.

The shelf isn't necessarily expensive to make.

It's expensive in terms of what you give up by making it.

That's an important distinction.

A shelf can be profitable in isolation.

If you made one shelf and looked only at:

Selling contribution: ₦20,000
Production cost: manageable
Profit: positive

you might conclude:

“Make more shelves.”

But the business isn't operating in isolation.

It has a limited amount of wood.

It has a limited number of machine-hours.

It has a limited amount of labour.

Every shelf therefore competes with the tables and chairs for those same resources.

The relevant question isn't:

“Does this product make money?”

It is:

“Is this the best use of the resources required to produce it?”

A profitable activity can still be the wrong activity

This principle extends well beyond furniture.

A business might have:

• a profitable product that consumes too much production capacity;

• a profitable customer who requires disproportionate service resources;

• a profitable order that occupies scarce machine time;

• a profitable sales channel that uses limited marketing capacity;

• or a profitable service that ties up employees needed elsewhere.

Profitability alone doesn't determine priority.

When resources are scarce, you also have to consider what those resources could have produced somewhere else.

That's opportunity cost.

What the analysis actually tells the owner

The recommendation isn't:

“Shelves are bad products.”

It isn't even:

“Never produce shelves.”

The recommendation is much narrower:

Under these particular resource constraints and demand assumptions, shelves are not the best use of the available capacity.

Change the circumstances, and the answer can change.

Give the business more machine-hours.

Give it more labour.

Change the contribution margins.

Change demand.

Improve the production process.

The optimal production mix may change with them.

That's why these decisions are worth analysing rather than reducing them to a simple ranking of products by profit.

The broader lesson

A business owner naturally asks:

“Which of my products is most profitable?”

But when resources are constrained, a better question is:

“What is the most valuable use of the resources I have?”

Those are not the same question.

And sometimes the answer to the second question is:

Produce less of something that makes money.

In this case, that meant producing zero shelves.

Not because shelves weren't profitable.

Because, under the current constraints, something else could make better use of the resources required to produce them.

That's where optimization becomes useful: it helps you look beyond whether an individual decision is profitable and ask whether it is the best decision available.