consultingwoodworker.com Blog

“No more tape measures!”

Sounds odd in a cabinet shop, but that’s where I taking one of my clients, and I’m rapidly becoming convinced that it could become the next major trend in custom shops. As part of working toward Lean Manufacturing, I started with material handling issues and have transitioned into measuring and marking.

One of the most common complaints I hear from shop owners and managers all over the country is that good workers are hard to come by. There are just not that many skilled cabinet makers out there. The reasons for this are many and varied and have been discussed widely in the trade magazines and online. For you, the business owner, the reasons are abstract, the results are quite real. I’ve actually seen help wanted ads for shops that state; “Must be able to read a tape measure.” My client is no less troubled finding good help than any of you, and making the cutting and milling phases of the job more efficient has only moved the bottleneck to the assembly area. So we have embarked on a program to eliminate the need for tape measures in the assembly area.

The process starts in design. The designers know how cabinets are built in this shop, and work closely with the CNC programmer at the outset of a new job to insure that the design is structured to maximize the capabilities of the shop.
In this particular shop, sides and vertical dividers are given a shallow dado to locate the top, bottom and any fixed shelves. The same process is used to locate vertical dividers. Working with the single cabinet production schedule discussed in the Sept 20th Blog, the assembler gets a set of parts that essentially can only fit together one way. All shelf, hinge and slide holes are already bored, and any pass throughs or grommet holes are also done beforehand on the CNC. In cases where the cabinet ends are not visible, pilot holes for screws can be drilled in the center of the dados, so no time needs to be spent making sure the screws hit their intended target.

It becomes far easier for my client to now hire and train assemblers. This process removes the need for the assembler to be a skilled cabinet maker. It eliminates having spacers cut to set fixed shelves or drawer slides. It obviates the error between Bob’s tape and Joe’s. It negates the bent hook from a dropped tape causing parts to be slightly skewed. Skilled employees are now free to concentrate on the associated millwork, scribes, headers and such for the job. Some may even be able to be moved into supervisory roles as appropriate, overseeing and training the new assembly crew.

As always, I’d be very interested in hearing your opinions on these ideas. Please feel free to post comments here on the Blog, or e-mail me your thoughts. Also, if you want to be notified when I post a new topic to the blog, please use the contact form on my website and I’ll be happy to add you to my mailing list.

In my last posting, I introduced my belief that Lean Manufacturing in the custom cabinet shop is tied to material handling. This time I’ll look at some examples to demonstrate what I mean.
In “traditional” cabinet making, sides are cut into rectangles, then carried to the next stations. These parts are drilled horizontally, then carried to a saw for notching out the toe kicks. Next they are picked up again and carried to boring machine, edgebanders and so on. With each step, the parts are lifted off a stack, processed through the step, then restacked.
Machines have helped reduce the time needed to cut, drill and band these parts, but the handling time is still there, and in all but the most sophisticated shops, it hasn’t changed much.
Nested based manufacturing represents the first step in reducing this handling time. Now, a single operator can perform many of these functions at one station. The handling time for the steps represented is now included in one. That one step does take somewhat longer, but the machine does the work, and the operator can be performing secondary operations. Also, instead of needing to reset various machines for each different cabinet, Nested based manufacturing means that every cabinet in a project can have different milling by simply calling up the right program. More time saved.
Most automated shops have about stopped at this point, and profit can be had here, but I’m going to look at taking this idea one step further along.
Given that modern software, coupled with modern machines can efficiently produce a single cabinet at a time, why not structure the entire shop to efficiently produce a single cabinet at a time? Before you scoff, think carefully about what I propose.
The nest is formatted to group all the parts of a cabinet together. They are cut, dadoed, bored, etc. as a group. The group is stacked on a tray and sent along a roller conveyor to the next station. There they are edge bored and banded if you dowel, or straight to the edgebander if you use screws.
Once milled bored and banded, they move along to assembly. Hinge plates and drawer slides are added and the box is built.
And consider further that since all the parts travel as a group, there is much less need for trying to label all the parts and search around looking for the ones needed. No more printing hundreds of labels that get torn and fall off. And the reduced stacking and unstacking helps keep surface damage down, whether or not you use prefinished materials.
A single shop drawing can have the CNC program name on it, or better yet, a barcode for the machine to read. This sheet travels with the parts to instruct the various stations and identify the cabinet.
This is something of a radical idea, but give it some thought this week. In my next blog, I will discuss my proposal for throwing out tape measures in the assembly area.

I enjoyed a rare opportunity at IWF last month to spend an hour walking the floor with the CEO of one of the industry’s fastest growing companies.

Among many other topics, he asked me my thoughts on lean manufacturing. I realized, as I answered him that I had no formal training in lean theory or technique, but I had ideas on what works. Like most of you, I had heard terms like Lean, Kanban and Six Sigma, but never really tried to quantify or define them. For me, it all comes down to a question of material handling. It has been my observation, through years of working with many different companies, that material handling is where Lean exists.

In my view, Lean Manufacturing means that each time a part is handled, every possible operation is completed at each work station. In an ideal custom cabinet shop, a CNC would drill, mill and cut the parts of a cabinet as a group. That stack of parts is immediately send along to edgebanding and/or edge boring. Finishing is the next stop, then that set of parts regroups in assembly, where hinge plates, slides and any other hardware is added prior to actually assembling the cabinets.

Playing Devil’s Advocate, he told me that nobody does it that way, and it didn’t make sense logically. I held my ground and told him that that is because most shops, especially smaller ones, do not take into proper account the time lost to material handling.

In next week’s Blog, I’ll discuss the actual cost of material handling and ways to minimize it.