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How high density storage can improve manufacturing efficiency

Workplace storage systems company Lista is turning the old adage, “Do as I say, not as I do” on its head when it comes to manufacturing products at its Holliston, MA facility. It’s more like “Watch how I do what I say,” as the company uses its own products to organize its manufacturing space for efficiency, improved throughput, and waste reduction. Through its lean initiatives, the company eliminates wasted effort, and then configures the space with the proper cabinets to increase efficiency, adhering to another old adage, “A place for everything, and everything in its place.”

Lean initiatives the basis for improvements
In today’s competitive environment, nimble manufacturers focus on continuous improvement, recognizing that, no matter where you are in the manufacturing cycle, work stations must perform functions and they can always be performed better. Regardless of any efficiency improvements that may have gone on in the past, there is always room to go back and update processes to streamline them further.

While its main assembly line has been efficiently laid out to handle 80 percent of the company’s product line, Lista establishes model manufacturing cells to evaluate the most efficient ways to assemble unique cabinets or workbenches. Those are defined as products that take more effort, feature more components, or are different in some way from standard products. The cells are equipped with everything the operators need to perform the specific function for which the cell is designed.

With the assistance of lean tools like value stream mapping and kaizen events, the company uses the model cells almost like a laboratory in which they can examine processes in minute detail, searching for ways to reduce waste. Kaizen events are usually performed with workers on the production line; other departments, including production and finance, are also enlisted to look at the particular cell with fresh eyes.

Many of these specific storage solutions were developed as part of the company’s “5S” workplace organizational and housekeeping methodology, a key component of Lista’s continuous improvement and lean manufacturing processes. Keeping in mind the 5S goal of reducing waste and optimizing productivity through maintaining an orderly workplace, a team evaluated which tools were needed for each particular work station. The process ensures that each cabinet is properly sized for specific requirements and that it is being used only for necessary functions. (We said goodbye to more than one drawer used to store empty soda cans.) Extra space gained from unneeded cabinets or drawers was used to bring work stations together to improve product flow.

One example is the Align® adjustable height workstations, which are equipped with either a hand-cranked or motorized bench. Lista set up a cell to see if the amount of foot traffic needed to assemble the workstations was excessive, and then used its own products to install the proper cabinets such that each tool would have a specific location in a particular drawer. Tools are outlined, so operators can see where the tool belongs and notice if it has not been put back after an operation has been completed. By installing and configuring these storage cabinets, the company increased the efficiency of the workstation used to assemble this unique bench by nearly 30 percent. See Figure 1.

Lista also uses its storage wall, shelf, drawers, and trays for point of use storage for the motors, actuators, control boxes, crank components, and linkages needed for the Align workstations. Separate work cabinets store all required testing equipment.

Prior to the use of the model cell, motors and accelerators were stored on a pallet rack, but not directly at the point of use. The components may have been about 20 to 30 feet away from the assembly location. They arrived in a cardboard crate, so a certain amount of foot traffic was necessary to access the pallet rack. Operators would use a mobile cart to collect what they needed for an hour’s work, usually about 4 or 5 sets. This resulted in a tremendous amount of wasted effort from walking back and forth, which was eliminated by storing the contents of the pallet rack in a storage wall at the assembly location.

While the amount of time needed to fetch parts may not seem significant, if you are repeating this movement all day, every day, for 250 days a year, it does add up quickly. Making the change was a significant time saver in assembling the bench. Like so many other manufacturers, Lista runs a very lean operation when it comes to labor, so building these benches in 20 to 30 percent less time means workers can be working on something else. The operation is an extremely dynamic one, in which operators are trained to work on multiple functions. Processing orders through the assembly line more efficiently means more can be produced in less time.  

There’s one more interesting feature about this particular cell – and one that has a nice symmetry. Lista is physically building the Align height-adjustable motorized work benches using Align height-adjusted motorized benches. The work surfaces that operators use to build the adjustable benches are themselves height adjustable. They were customized to fit the application; built narrower than most standard work benches, the top is wrapped in industrial carpet so the product’s paint doesn’t get scratched during the assembly process. See Figure 2.

Vertical storage helps manufacturing minimize required floor space
Considerably more attention goes into detailed planning of manufacturing cells in this day and age compared to 15 years ago, due in part to lean efforts as well as a common desire to minimize floor space. Like many manufacturing facilities, floor space is at a premium at Lista, so each time a manufacturing cell is built for a particular product, the goal is to use the minimum amount of space necessary to build the product, while creating a good working environment and ensuring that material can be brought in and out with a good product flow.

As Lista has grown, it has added to its manufacturing space, but growth and expansion within the facility requires continually seeking out areas that can be made more efficient. Using vertical storage or a storage cabinet that is only as big as needed greatly improves efficiency. Like squeezing a sponge to wring out every drop of water (or space), we are storing tools and materials more densely, and moving cabinets in and out on casters, so when they are not being used they can be stored underneath the workbench. The goal is to have everything needed while working just a half-step away.

Point of use storage speeds fabrication
As a sheet metal manufacturing facility, Lista punches metal to generate a required shape in a flat pattern, which is then bent, welded, and painted. Each process uses multiple pieces of equipment, depending on the product being made. And next to each of these pieces of equipment is at least one Lista storage cabinet, used to store needed tools, for example bending tools (which tend to be long, narrow, and heavy), wrenches, measuring instruments, and screwdrivers.

In one area of the building, 30 pieces of equipment are located, each with a Lista cabinet that stores tools at the point of use. Depending upon the equipment, the cabinet could be tall and narrow, or short and wide, with a work surface or cabinet mounting under a bench. In this area, operators are constantly changing over machines. Sometimes, they set up and only use the equipment for a small number of runs and then they have to set up again. There is a continuous process of determining what is to be made next, pulling up drawings and programs on a particular press, installing tools, and then running the job, removing the tools – and then completing the process again to bring the product to the next step. See Figure 3.

Locating the Lista cabinets at the point of use with everything they need for a particular operation has increased efficiency in this area, especially compared to several years ago when a central storage unit held all the hand tools that might be needed for an operation.

For example, one work station was developed to manufacture a newly redesigned hanging cabinet, which was being updated based on feedback from the field. Incorporating the new features, and making it efficiently manufacturable, became a major initiative, involving collaboration between the engineering and manufacturing teams. The team looked at every component to improve the throughput and reduce the setup, run, and handling times, increasing efficiency throughout the manufacturing processes.

The team built a model cell for the hanging cabinet with everything that the operators would need right there at the point of use. The cell includes an adjustable height scissor lift designed to be ergonomically correct for welding, as well as a hanging cabinet to store tools, so operators no longer have to walk across the floor to get a tool or measurement instrument. Once again, the symmetry – using a hanging cabinet to make a hanging cabinet.

Shining a light on improving efficiency
Hopefully the examples given shine light on areas where efficiency can be improved by using high density storage. Of course it’s clear that Lista is a bit spoiled because of its immediate access to a range of storage options, perfectly customized to each operation. If we have an application and we need to store tools in a particular manner, it’s easily possible to get just the right cabinet in its proper place. But the basic concept still applies – there should be a place for everything – and everything should be in its place.

This story was contributed by Phil Burr, Lista