Deciding What to Outsource and What to Keep In-House

Published by
Throne of Profit Editorial

Reviewed by
William Hassell
Founder & Chief Editor, Throne of Profit

Almost every part that leaves a shop passes through a decision most owners make by habit rather than on purpose: which operations run under your own roof, and which go outside. Plating, heat-treat, anodize, powder coat, specialty grinding — for each one there's a real choice, and most shops default into whatever they've always done. That default is where margin and lead time quietly leak. Outsourcing isn't a cost decision or a capacity decision alone — it's the trade between the two, and the shops that get it right decide it deliberately, part by part, instead of by habit.

The pull runs both directions. Send too much outside and you hand away margin, lose control of your schedule, and wait on a vendor's queue for parts a customer is calling about. Keep too much inside and you tie up a machine that would earn more doing the work you're actually good at. The right answer is rarely all-in or all-out — it's knowing which operations belong where, and why.

   THE OUTSOURCE / KEEP DECISION

   an operation (plating, heat-treat, secondary op)
        │
        ├─ core skill + steady volume ──► keep in-house (control + margin)
        ├─ specialized / low volume ─────► outsource (skip the fixed cost)
        └─ swings with the season ───────► flex: in-house base, farm out peaks

Owner symptoms

• Jobs sit waiting on an outside vendor while your own machines run light.

• You own equipment for a process you run a few times a month and can't fully load.

• Whether an operation goes out or stays in depends on who quoted it, not on a rule.

Why this happens

Most outsourcing choices were never really decided — they were inherited. A shop bought a machine for one big customer years ago and still runs the process because it's there. Another sends heat-treat out because it always has, even though volume now would justify a relationship that shortens the queue. The trade is invisible day to day: the cost of a tied-up machine doesn't show on any invoice, and the lead-time hit from a vendor's queue doesn't show until a customer is waiting. So the shop keeps doing what it did last year.

Common mistakes

• Deciding once and never revisiting — volume, vendors, and your own capacity all shift, but the make-or-buy call stays frozen.

• Counting only the machine price, ignoring the floor space, operator hours, maintenance, and the setups it steals from core work.

• Chasing control at any cost — keeping a specialized process in-house for pride when a vendor would be faster and cheaper.

• Ignoring lead time — outsourcing to save a few dollars a part while adding a week to every job that needs it.

• Treating every operation the same instead of judging each on its own volume and margin.

Business consequences

The cost of getting this wrong compounds quietly. Over-outsource and your lead times stretch to your vendors' queues, your margins thin on work you could have kept, and you lose the ability to promise a date and hit it. Over-insource and you carry fixed cost on equipment that never earns its keep. The owner who decides each operation on purpose keeps the core work that carries margin and controls the schedule inside, sends the specialized low-volume work out, and stops paying — in cash or in days — for the mismatch.

How experienced operators think about it

They don't ask "in or out" in the abstract; they ask it one operation at a time, against two questions. First: is this a core skill we do well and load steadily? If yes, keeping it protects both margin and schedule. Second: what does the trade actually cost — the fully loaded price of doing it inside versus the price plus lead time of sending it out? Specialized, low-volume, capital-heavy operations like plating usually belong outside; few small shops can load a plating line. Steady, core work usually belongs inside. The interesting cases sit in the middle, where the answer is flex — a base load in-house, peaks farmed out, so you're never idle and never underwater.

Practical actions

1. List every operation on a typical part and mark each as in-house, outsourced, or split — then ask whether that's a decision or just a habit.

2. Load the real cost of in-house, not the sticker price: operator time, floor space, maintenance, and the core jobs a setup displaces.

3. Add lead time to the outsource side — a vendor's queue is part of the price, and on a hot job it may be the whole price.

4. Keep the core, send the specialized out. Protect margin and schedule on what you do well; skip the fixed cost on what you'd run a few times a month.

5. Revisit the split each season. Volume that once justified outsourcing may now justify bringing it in — or the reverse.

Questions every owner should ask

• For each outside operation, would bringing it in shorten lead time enough to justify the cost — and could I keep the machine loaded?

• For each in-house process I run rarely, is the equipment earning its keep, or displacing better work?

• When a job runs late, how often is it waiting on an outside vendor I could have kept inside?

Frequently asked questions

How do I know if a process is worth bringing in-house instead of outsourcing it?
Start with volume and load. If you'd run the new equipment steadily and the work is close to your core skills, bringing it in usually shortens lead time and protects margin. If you'd run it a few times a month, the machine sits idle most of the time and you're carrying fixed cost for occasional convenience — a vendor almost always wins. Then load the real numbers on both sides: the fully loaded in-house cost against the vendor's price plus their queue. Deciding by feel is how shops end up with a heat-treat oven they barely run.

Should I ever keep an operation in-house even when outsourcing is cheaper per part?
Sometimes, yes — but be honest about why. If the operation controls your lead time on hot jobs, or the vendor's queue routinely makes you late, the control can be worth paying for. What isn't worth it is keeping a process inside out of pride or history when a vendor is faster, cheaper, and reliable. The test is whether the in-house control buys you something a customer would pay for — a shorter, more dependable lead time — not just the comfort of doing it yourself.

Related articles

• Running a Profitable Small or Midsize Manufacturing Business — the pillar.

• Adding a Second Shift Without Losing Control of Quality — another way to add capacity before you outsource.

• Keeping the Shop Steady Through Slow Stretches — managing the volume swings that shift the make-or-buy line.

• Why Jobs Take Longer Than You Quoted — the general lead-time problem.

• Where Time Leaks on a Typical Job — where outside operations quietly add days.

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