How to Decide Who in the Shop Should Hold What

Why this matters

Most shops acquire credentials reactively. Somebody gets certified because a job demanded it, somebody else because they asked to, and the roster ends up shaped by history rather than by what the shop sells. The bill arrives on the day one person is out and an entire service line stops with them, or on the day a customer asks for something you have sold before and nobody currently on payroll can legally perform.

This is a design problem, not an inventory problem. A credential register tells you what you hold. This tells you what you should hold, and it is the diff between those two lists that you actually work. See related: How to Build a Credential Register for a Small Shop.

Step 1: List the work you sell, not the trades you claim

Start from your last twelve months of invoiced work, rolled up into service lines a customer would recognize. Six to ten lines is usually the whole shop. Do not start from your trade classification or your website, because both describe the business you say you are in, and the credential question is decided by the work you actually performed.

Attach one number to each line: the count of days in the last twelve months on which that line was sold at least once. Days, not revenue, not job count. Days is the unit that predicts outages, because a credential gap only hurts on a day the line is needed. Skipping this leaves you sizing coverage by how much a line bills, which routinely over-protects one high-ticket line sold four times a year and under-protects the routine line that touches every board.

Step 2: Find the trigger for each line, not the credential

For each line, write the sentence that makes a credential required. That sentence has a subject (the work), a threshold or condition, and an authority. You are looking for the trigger because triggers are stable and credential names are not: the same work is gated by a "journeyman" credential in one state, a "registration" in the next, and nothing at all in a third.

Three federal triggers show up across trades and are worth writing precisely, because they do not vary by state:

• Opening a refrigerant circuit on stationary equipment requires the individual doing it to hold Section 608 technician certification under 40 CFR Part 82 Subpart F. That certification does not expire, which makes it the rare register row with no renewal date.
• Renovation that disturbs painted surfaces in housing or a child-occupied facility built before 1978 brings the work under EPA's Renovation, Repair and Painting rule at 40 CFR Part 745 Subpart E, which requires both a certified firm and a certified renovator on the job. Two separate credentials, two separate clocks.
• Operating a commercial motor vehicle subject to 49 CFR Part 391 requires the driver to hold a current medical examiner's certificate, with the periodic examination interval capped at 24 months under 49 CFR 391.45 and often certified for a shorter term when a condition is being monitored.

Everything else on your list is state or local, and the authority is your licensing board, your county, or the municipality where the address sits. Write down which one, by name, for each line. See related: The License and Bonding Requirements That Vary by Jurisdiction.

Step 3: Sort each line into company-held, person-held, or both

Three buckets, and the sorting drives everything downstream:

• Company-held. The credential attaches to the business entity. A firm certification, a business licence, a contractor licence issued in the company's name. These survive a resignation.
• Person-held. The credential attaches to an individual and leaves with them. A journeyman card, a technician certification, a driver's medical certificate.
• Company-held resting on a person. The dangerous middle. Most contractor licences issued to a company are conditioned on a named qualifying individual whose own credential and continued association hold the company licence up. It sits in your company folder and behaves like a person-held credential the day that person leaves.

Mark the third bucket explicitly. It is the single largest source of surprise in a small shop, and it deserves its own treatment. See related: The Single Licence Holder Problem.

Step 4: Set the minimum holder count per line

This is the rule the whole method turns on. Unit of analysis: one credential line, evaluated once per quarter. Set the minimum holder count N as follows:

• N = 1 only if the line was sold on fewer than 12 days in the last twelve months and every instance can be deferred or subcontracted without breaching a commitment you have already made. Both conditions, not either.
• N = 2 if the line was sold on a monthly or more frequent cadence.
• N = 3 if the line was sold weekly or more often, or if losing it stops other lines from running.

Step size when you are below N: add one holder per line per quarter. Not two, and not the whole gap at once. Training capacity, exam scheduling and the hours a candidate has to accumulate are all real constraints, and a plan that closes four gaps at once closes none of them.

Company-held lines get N counted differently: the count is the number of jurisdictions you need the credential in, not the number of people. A business licence in three municipalities is three rows, each with its own renewal date, and each one is a single point of failure that no amount of internal redundancy fixes.

Step 5: Pick the holder by constraint, not by seniority

The default choice is the most senior person, and it is usually wrong. Pick against three constraints in this order:

1. Who is already close to eligible? Most trade credentials gate on documented hours of experience under supervision. The person with the hours is years ahead of the person with the title.
2. Who is on the board on the days that line runs? A credential held by someone who dispatches, sells or estimates does not cover a field outage. It covers a paperwork outage, which is a different problem.
3. Who is likely to still be here in three years? Not a loyalty test, an honest read. Person-held credentials are an investment in a person, and the shop keeps the redundancy only as long as it keeps the person.

Where two candidates tie, prefer the one whose route to the credential also removes a supervision constraint on your dispatch board. A second credentialed field technician raises your supervision ceiling and closes a coverage gap with one action.

Step 6: Sequence by lead time, prioritize by frequency

These two orderings disagree, and the disagreement is the point. Frequency tells you which gap costs the most while it is open. Lead time tells you which one has to start first. Start the long-lead credential immediately even when it ranks second or third on frequency, because it is the only one where a quarter of delay is a quarter of delay.

Worked example: six lines at a twelve-person shop

Twelve people, seven of them in the field. Twelve months of invoiced work rolls up to six lines, and here is the sheet after steps 1 through 4:

Run the rule against each row rather than eyeballing it. Refrigerant work at 173 days is weekly or more often, so N is 3, and 7 of 7 field technicians hold it because the certification is inexpensive to obtain and never expires. Permitted replacements at 104 days is also weekly or more often, so N is 3 against 2 holders, a gap of 1. The pre-1978 renovation line at 12 days does not qualify for N = 1: the N = 1 test needs fewer than 12 days and deferrability, and 12 is not fewer than 12, so it lands at N = 2 against 1 certified renovator. That row is the one an eyeball would have waved through, and it is a genuine gap.

Four gaps, one per quarter under the step rule, so a four-quarter plan. Now sequence by lead time and the order inverts:

• Start now, finishes last: the third credentialed individual for permitted replacements. The candidate needs documented supervised hours plus an exam, and that is measured in years, not quarters. Ranked second on frequency at 104 days, started first anyway.
• Start now, finishes inside the quarter: the third medical examiner's certificate. Ranked first on frequency at 250 days, and it is a scheduled physical exam.
• Quarter two: the second certified renovator. A short accredited course.
• Quarter three: the third municipal licence. Application lead time set by the municipality, not by you.

Note what the frequency ranking would have produced on its own: driving first, permitted replacements second starting in quarter two, which pushes a multi-year credential three months later for no gain. Frequency ranks the pain. Lead time schedules the work.

How to verify you got this right

Three checks, all runnable in an hour with the sheet in front of you.

The absence test. For each line, name the specific people whose simultaneous absence stops it. If any line resolves to one name, N is not met for that line regardless of what your holder count says, because the count included someone who no longer holds it, is not in the field, or is the same person twice under two roles.

The reverse trace. Pick five invoices at random from the last quarter and, for each, name the credential the work triggered and the person on that job who held it. This catches the failure the forward method cannot: a line you sell but never wrote down. If a line surfaces that is not on your sheet, your step 1 list came from memory rather than from invoices, and it needs redoing.

The horizon check. Sort every person-held row by expiry and read the next two quarters. A holder count of 3 where two expire in the same month is a holder count of 1 with extra steps, and this is common because people who trained together renew together.

Re-run the whole method annually, and any time you add a service line or lose a credentialed person. A sheet that has not moved in two years is describing a shop you no longer run.

References

• 40 CFR Part 82 Subpart F, EPA Section 608 technician certification for work on stationary refrigeration and air conditioning appliances
• 40 CFR Part 745 Subpart E, EPA Renovation, Repair and Painting rule, firm and individual renovator certification for pre-1978 target housing and child-occupied facilities
• 49 CFR 391.45, FMCSA periodic physical examination requirement for drivers operating commercial motor vehicles
• Your state licensing board and each municipality where you hold or need a business licence, for classification scope, experience-hour requirements and application lead times
• See related: How to Build a Credential Register for a Small Shop, The Single Licence Holder Problem, The Scope a Credential Actually Authorizes