Think about a franchise business such as one of the multitudinous fast-food operations. You could buy a hamburger at one outlet in Portland, Maine, and a burger at another in Portland, Oregon, and they are almost exactly the same. The tools and the methods are standardized.
Job shops aren’t like that. Each is its own thing. Each does things differently. But there are some commonalities.
Gardner Business Intelligence has surveyed more than 400 job shops across the United States as part of Modern Machine Shop’s Top Shops benchmarking program. The “Top Shops” are the top 20% of the participants, scored on 14 metrics.
What follows is a numeric look at what we’ve found. Please keep in mind that:
The percentages cited are median numbers.
None of these things necessarily make any given firm a Top Shop – but it probably wouldn’t hurt to consider what these numbers show and compare it with your operation.
For the most part, this is what is happening at independent operations, not cookie-cutter franchises. Results may vary.
What They Are; What They Do
Top Shops have a median batch size of 95 parts. These parts generally fall within a 6-inch cube (65%) and a tolerance of 0.0005 inch (40%).
One interesting thing to note on the subject of tolerances is that 0.0001 inch is actually a fairly common spec, as it is reported by 33%, which makes it the second-most common tolerance.
Going back to the cubic dimensions, following the 6-inch cube are the following cubic sizes: 12-inch (56%), 18-inch (45%), 24-inch (35%), 36-inch (26%), 48-inch (16%), and >48-inch (15%). This shows a pattern of larger sizes being less commonly addressed by job shops.
These businesses, which are mainly independent job shops (48%), followed by contract shops (40%) and captive shops (11%), service an array of industries.
Aerospace is the single biggest market, at 56%. This is followed by machinery/equipment manufacturing at 49%. Military is the third-most served industry segment, at 44%. (Remember: As these are job shops, they likely work for many different industries and make parts of different sizes, so the numbers add up to more than 100.)
Automotive and medical are both at 39%, closely followed by oil-and-gas-fired mining machinery at 36%.
As industries served follows demand, it is a fairly safe supposition that because of exogenous conditions – from the war in Ukraine to the pandemic to the global energy supply to the electrification of the auto fleet – these top six markets are likely to not only remain at the top but increase as a percentage of business.
(Perhaps something of a talking point – or a bit of interesting trivia – is the industry with the least amount of business for the job shops: furniture manufacturing, at 6%. Given the increase of remote work or hybrid situations and reduced in-office hours, the demand for office furniture is not likely to grow.)
It is worth knowing that when it comes to customers, these facilities evidently do an exemplary job: the customer retention rate is 98%.
With regard to types of equipment, vertical dominates for rotational tools, with 89% reporting having vertical machining centers (VMCs), and horizontal for rotational workpieces, with 77% having horizontal turning centers (HTCs).
Although CNC machines have been commercially available for more than 50 years, the types of machines that tie for third in terms of being on shop floors are lathes and milling machines – without CNC – at 62%.
They are followed by horizontal machining centers (HMCs) at 58%.
Taking the number of VMCs, HTCs, and HMCs into account, the dominance of CNC is clear. The median number of CNC machine tools is 16, with an age of seven years.
What’s more, 86% of respondents report having CAM software (and 88% CAD), so these shops are well into CNC operations.
Additionally, 58% respond that they perform lights-out and unattended machining, so it is clear that computer control is part of their operational regime.
While it isn’t entirely surprising that plasma/oxy-fuel machines come in second from the bottom at 7% – after all, these shops are more concentrated on machining so there isn’t a whole lot of plate cutting occurring – what is somewhat surprising is that at the bottom, at 5%, are twin-turret machines. This could be a function of twin-spindle machines lending themselves to volume production and so are probably perceived to be insufficiently flexible for job shop applications.
In the inspection arena, there is something that is both surprising and expected in the top spot for equipment: optical comparators, at 73%. This is surprising because compared to the coordinate measuring machine (CMM), which is in the second spot at 69% (these CMMs are in a quality department; shop-floor CMMs are back in sixth place at 27%, ahead of a portable measuring arm at 24%; nothing is last, but still 6%), the optical comparator is a tech that’s been around for 100 years – which is not to say that it hasn’t been improved in that time. Its ranking is not surprising because when it comes to speed and flexibility, they are highly useful tools.
One technology that has room for growth in the job shop arena is 3D printing, or additive manufacturing. Only 32% report they use the technology. Of that number, 60% are using desktop units for printing polymer materials. Stand-alone machines, with more substantial work envelopes, are at 39%. However, when it comes to additively building metal components, there is something of a dearth, with 9% reporting having the equipment. Still, there are 68% of the shops not using 3D printing at all.
As previously mentioned, aerospace is the leading industry served, which probably goes to the point that 95% report machining aluminum. Additionally, primarily in aero, high-temperature alloys (58%) and titanium (53%) are among the materials most processed by the shops, as they are seventh and ninth in the top 10.
Rounding out the top 10 of metals machined are stainless steel (2), mild steels (3), brass (4), tool steel (5), bronze (6), copper (8), and cast iron (10). Only cast iron is below 50%, at 46%.
When it comes to skilled staff, only 18% reported that they have no shortage. Of those firms, they took a variety of approaches to address the shortage, with the predominant strategy being cross-training (80%).
In terms of improvement methodologies being undertaken by these shops, the numbers are somewhat low. Fifty-three percent say that they have some continuous improvement activity. But then the numbers fall, with 42% performing 5S workplace organization, 32% benchmarking, and 30% cellular manufacturing.
At the very bottom is lean manufacturing (5%), which arguably means that there are some huge opportunities for some shops to improve their operational fitness.