Job shop manufacturing is a common and demanding way of making things, and it is one that generic manufacturing advice often does not fit. This piece explains what a job shop is, how it works, and what makes it hard to run well.
What a job shop is
A job shop is a manufacturer that produces a wide variety of products in small quantities, usually to customer order. Rather than running a few products in high volume, a job shop runs many different jobs, each potentially unique or nearly so, through a shared set of capabilities. A machine shop taking on varied custom parts, a fabrication shop, a contract manufacturer handling diverse short runs: these are job shops. The defining quality is high variety and low volume.
How a job shop is organised
A job shop is typically organised by capability rather than by product. Equipment is grouped by what it does, all the machining here, all the welding there, all the finishing in another area, and each job travels through whichever sequence of capabilities it needs. Because every job is different, jobs follow different routes through the shop. One job needs machining then finishing; the next needs cutting, welding, and inspection. This is the opposite of a production line, where one fixed flow makes one product family. A job shop is a flexible set of capabilities through which many different jobs are routed.
Why a job shop is hard to run
That flexibility is the job shop's strength, and it is also the source of its difficulty. Several things are genuinely hard.
Scheduling. With many jobs, each taking a different route through shared work centres, scheduling becomes a complex sequencing problem. The same machine is wanted by several jobs; jobs compete for capacity; a delay on one job ripples into others sharing its route. Job shop scheduling is constantly changing and hard to keep right by hand.
Quoting and costing. Because jobs are varied and often one-off, there is no standard cost. Every job has to be estimated, and then its actual cost, material, machine time, labour, has to be tracked against that estimate. A job shop that does not cost jobs individually does not really know which work is profitable.
Visibility. With many jobs in progress, each at a different stage on a different route, simply knowing where every job stands is a challenge. Customers ask for status; the shop has to be able to answer.
Utilisation. A job shop wants its capabilities well used, but variety makes load uneven, some work centres swamped, others idle, and balancing that is ongoing work.
What a job shop needs to run well
These challenges point to what a job shop needs from a system: per-job estimating and costing, so each job's profitability is known; scheduling that can handle many jobs on varied routes through shared work centres; clear, current visibility of where every job stands; and a way to track actual time and material against each job as it runs. A job shop run on spreadsheets tends to lose grip on exactly these, the schedule drifts, jobs are costed by gut feel, and status is whatever someone remembers. We cover the software in our piece on job shop manufacturing software.
The takeaway
Job shop manufacturing makes a wide variety of products in low volumes, to order, through a shared set of capabilities that jobs are routed through individually. Its flexibility is its value and its difficulty: scheduling, per-job costing, and visibility are all genuinely hard, and they are what a job shop needs its system to handle. For how we approach job shop manufacturing, see our manufacturing work.