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Where to look for the next boost in productivity?

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Operations Excellence by Sepp Gmeiner
Sepp Gmeiner is a partner with Lignum Consulting. For feedback, questions and/or suggestions please email s.gmeiner@lignum-consulting.com
When investing in cabinet manufacturing plants, panel storage and retrieval systems combined with nesting CNC routers are very common now. On panel saws, the industry is still undecided. There are plants that install saw and nesting machines, and others that do everything with nesting routers. By having the board storage and retrieval system working in concert with nesting machines/panel saws you are pretty much state-of-the-art here.
The next step in the process chain is edgebanding. By now edgebanders are not the question; it is the infrastructure around the edgebander. A simple mechanical return conveyor is no longer the state-of-the art solution. Fully integrated and automatic lines are, most of the time, cost prohibitive for cabinet producers of 100 – 200 cabinets a shift. The solution now is smart material handling equipment. The operator places the part in the right orientation on the infeed conveyor and lets go of it. The equipment reads the parts label, feeds the part into the machine, selects the required edge from a multiple choice magazine and calls up the right machining program. As the part exits the edgebander, it is either automatically stacked at the outfeed, or returned for an additional edge.
Flexible machines like this enables batch-sizes as low as ½ -3 kitchens per batch.
The challenge for the future is how to economically link the nesting machines with these edgebanders. One of the challenges here is how to merge two nesting machines to serve one edgebander. In most cases we stack down, sorting the parts and feed the edgebander. Reducing the labour content by eliminating this stack-down and refeed requires major capital investment. The sufficient ROI on such an investment is typically not obvious.
For this article I will ignore the requirement in the finishing room. Sanding, spray application and curing are often very labour intensive processes. I will address it separately in another future article.

Assembly and warehouse
To complete the process, we need to assemble and ship the product. In trade shows, we sometimes see fully automatic assembly lines, but I have not seen them in practice in North America. I believe there are none in the volume range of 100-200 cabinets per shift.
In this context, the assembly process includes:
Drill and inserting dowels
Mount hinge plates
Mount drawer slides
Assembly the cabinet
Insert adjustable shelves
Insert drawer boxes
Hang doors
Install extra hardware (like waste bins, spice racks…)
Package (boxes, corner protectors, wrapping etc.
Stack cabinets for storage or shipping

All these individual tasks are simple and each could be done in seconds per cabinet. However, when you observe your operation, you see why it takes more than a few seconds.
The operator needs to:
Identify the next line item according to the work order
Look for the parts needed (if not found – pick another cabinet and start over)
Identify the parts/cabinet to match to the order
Understand what needs to be done

It is very obvious that these are all non-value added tasks, or waste as Lean manufacturing teaches.
You can imagine how fast and productive the assembly line would operate if all parts are the right quality, complete and in the right sequence and in reach of the operator when he/she needs them (fit & complete).
We will have more assembly line automation in the future. However, it must be clear that an automatic assembly line is much more sensitive to part shortages and out of tolerance components. People at the assembly line are much more flexible and adaptable to the needs on an assembly line.
Recently, I participated at a plant tour organized by the WMCO at the Toyota assembly plant in Cambridge, Ontario. When watching the assembly process and the flow, you see how much engineering, continuous improvement and investments went into this plant. Cars obviously have many more parts than a kitchen or a cabinet. The type of challenges however, are in principal, the same. As they produce to order from their dealer network (pull), they have to deal with product variety as much as the cabinet industry does. They deal with different models (i.e. RAV4 vs. Lexus) by assembling them on different lines. Our equivalent would be to run tall cabinets, 
corner cabinets, base 
cabinets and wall cabinets 
on different lines.
During the plant tour it was very obvious, how much effort was put into supplying the line with the right components. The assembly workers did not have to look for their parts. They could focus on the few tasks they had at that moment to complete within the assigned time. An army of people kept feeding the line. Multiple, escalating warning systems and organizational tools were in place to keep the line going. The risk of a line stoppage was ever present, but with a culture of THIS MUST NOT HAPPEN, it happens very rarely.
In comparison to many of the cabinet shops, we push the material to the assembly line and let them sort it out. We are far away from the level of automation and use of robotics in the cabinet industry that  we see in the automotive industry.

Where to start?
Improving any assembly line requires that we must focus on having 100 per cent availability of all the parts. This typically does not require major capital equipment. What it needs is organization and the resources to focus on getting all parts, hardware and subassemblies to the assembly line on-time and in the right sequence.
For smaller companies this can be done manually with printed lists and will power. For medium-to-large assembly lines and more complex products, we also need competent software support. These software systems are Manufacturing Execution Systems (MES).
The suitable systems guide the operators through the parts requirement and informs the down stream operator what is the next (and most urgent) product to be available to assemble. It can prevent a cabinet from being assembled before the doors are ready. If the finishing department is working on orders where key hardware has not been received, it appears that everybody is busy and productive, but there is nothing to complete.
Starting a product which cannot be completed will lead to incomplete cabinets blocking the floor space around the assembly line and reduces productivity on the line.
It seems this practice is acceptable in cabinet shops. Just imagine how this will play out in a car assembly plant. It would not work at all! Just because we can somehow keep on going on the cabinet line, and we probably don’t know how much extra this imperfection costs, we are not addressing it with the attention it deserves.
A cabinetmaker in a very small shop, will first check if everything is available before assembling. On mid-to-large size (50-200+) operations this cross checking will become too complex for people to manage. MES software will do this efficiently, accurately and quickly.  Recent plant tours organized by the 
CKCA have shown some excellent examples of 
these applications.

Summary
As board storage and retrieval systems with integrated nesting and panel saws are becoming more common, and edgebanding has more smart material handling systems, we are looking for the next area of improvement with high return on investment. This is in my opinion optimizing the assembly operation, specifically improving the material flow and supply to the assembly line.
This will require foremost implementation of appropriate software linked to accurate product and order data, clear organization, people training  combined with some reasonable upgrades on equipment and lay-out.
By getting material supply to the line under reasonable control (fit and complete), the flow (capacity, output) and productivity (labour content) will increase substantially. If more capacity is required after that, you will see where you need faster and better assembly equipment.

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