How high density storage can improve manufacturing efficiency
Phil Burr from workspace storage company Lista outlines how the company makes use of its own products to improve workflow and reduce footprint.
US-based 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, Massachusetts facility. The company uses its own products to organise its manufacturing space for efficiency, improved throughput and waste reduction. And through its lean initiatives, the company eliminates wasted effort and then configures the space with the proper cabinets to increase efficiency.
Lean initiatives the basis for improvements
In today’s competitive environment, nimble manufacturers focus on continual improvement, recognising that, no matter where you are in the manufacturing cycle, workstations 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 where it 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 organisational and housekeeping methodology, a key component of Lista’s continual improvement and lean manufacturing processes. Keeping in mind the 5S goal of reducing waste and optimising productivity through maintaining an orderly workplace, a team evaluated which tools were needed for each particular workstation.
The process ensured that each cabinet was properly sized for specific requirements and that it was being used only for necessary functions. As a result, the company bid adieu to more than one drawer used to store empty soda cans. Extra space gained from unneeded cabinets or drawers was used to bring workstations together to improve product flow.
One example is the Align adjustable height workstations, which are equipped with either a hand-cranked or motorised 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 were 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.
The company also uses its storage wall, shelf, drawers and trays for point of use storage for 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 nine to 10 metres 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 four or five 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.
The amount of time needed to fetch parts may not seem significant, but when you are repeating this movement throughout each day for 250 days a year, it does account for a significant amount of time. Making the change was a considerable time saver in assembling the bench. Like so many other manufacturers, Lista runs a very lean operation when it comes to labour, so building these benches in 20 to 30 percent less time means workers can be working on something else. The operation is quite dynamic, with operators trained to work on multiple functions. And processing orders through the assembly line more efficiently means more can be produced in less time.
The company is also physically building motorised workbenches using Align height-adjusted motorised benches. Even the work surfaces that operators use to build the adjustable benches are height adjustable. They were customised to fit the application: built narrower than most standard workbenches, the top is wrapped in industrial carpet so the product’s paint does not get scratched during the assembly process.
Vertical storage helps manufacturing minimise 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 minimise floor space. Like many manufacturing facilities, Lista’s floor space is at a premium, 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.
Using vertical storage or a storage cabinet that is only as big as needed greatly improves efficiency. The company stores tools and materials more densely, and moves 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. Next to each of these pieces of equipment is at least one storage cabinet housing bending tools, wrenches, measuring instruments and screwdrivers.
In one specific area of the building at least 30 pieces of equipment are located, each with a complete tool storage cabinet. 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 continual 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.
Locating the cabinets at the point of use with everything needed 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 workstation 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 manufacturing-efficient, the workstation 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 set-up, run and handling times, and increase 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. Thus another symmetry has been created – using a hanging cabinet to make hanging cabinets.
These changes in high-density storage have helped Lista considerably improve work efficiency. And by applying the basic concept of ‘a right place for everything and everything in its rightful place’, the facility has set up immediate access to a range of storage options that have been customised to each operation.
Phil Burr is the MFG engineering supervisor of Lista International.