Acquiring new sheet metal forming machinery has benefits — and possible pitfalls — for most HVAC construction contractors.
They hope the new equipment will increase capacity, improve productivity and boost profitability. But new equipment poorly placed or underused can actually cost more than it returns.
Lean manufacturing techniques have been successfully applied for many years, but it is still relatively new to HVAC construction, especially to sheet metal works and ductwork fabrication companies. Lean offers great possibilities to improve productivity if implement correctly. Running a shop using lean techniques is a different way of thinking about how work is fabricated. When lean is taken seriously in a shop, productivity will improve by 30 percent or more.
When new, or even used, equipment is being considered for a lean-operating shop, here are 10 — plus an extra half — key considerations.
1. Do you really need it? Purchasing new equipment is always exciting, just like buying a new car, but is there a better way to achieve fabrication goals? A basic lean approach is to use creative thinking rather than money. By looking in detail at the way material is fabricated, one may discover that more productivity can be gained by applying such lean tools as five-S and “Kanban,” without buying new equipment.
Consider used equipment as a better alternative than purchasing new. Used equipment may be especially useful where the need is low, such as in a line of products made infrequently. Adding used equipment for a product line not made as often could free up a better machine for the fabrication of the main product lines.
2. Listen to the experts. Involve those workers who use and/or maintain the equipment every day in any decisions to acquire new equipment. This gives trust and ownership to the operators and they in turn can look for ways to implement lean.
3. Supersize is not wise. Some HVAC market contractors pay too much for a machine with great capabilities that is used only 10 percent of the time. You don’t need one super machine to run large volumes of duct super fast, unless you only produce one type and size of duct. Smaller equipment offers more flexibility to meet the variable flow demands and smaller batches. It wastes resources to have a fast machine when the operator has to stand at the machine instead of doing a different task.
A “fast” machine will often sit idle while the rest of the process gets caught up. Look for equipment that fits a specific task, has limited setup requirements and fits well within the rest of the value stream (Lean talk for the fabrication process).
4. Focus on product “flow” in small batches. This is counterintuitive to traditional shop process thinking. Lean organizes the work, not by function (welding, insulation, etc.), but by product type. Lean seeks to eliminate waste, which include: fabricating sheet metal products too soon, products waiting, people movement as well as material movement, unnecessary process steps, inventory, and, of course, defects. This might mean:
- Instead of running expensive machines like a plasma cutter at near capacity, it may be better operated at 80 percent capacity or less so it balances the workflow through the shop.
- Building one fitting at a time rather than many fittings in a batch.
- Do not build products until the field needs it, instead of fabricating the product weeks ahead and stockpiling it at the shop or sending it to the jobsite early.
- Matching the material fabrication rate to the capacity of the slowest station rather than running each area independently and stockpiling work-in-progress inventory between stations.
5. Stop the “treasure hunts.” To minimize employees searching for items, lean manufacturing seeks to put the tools needed for running or adjusting equipment at the point of use, meaning right on or next to the equipment itself. Pedestrianism is not work. You don’t want to pay people to walk around. Yet many contractors do and rarely try to reduce the travel time. Often, as much as 75 percent of the labor in the shop is hunting and waiting. Neither adds value to the product.
If the equipment manufacturer is doing lean, they will understand and design their equipment for this need. If not, look at what tools are needed and if there is space sufficient on the equipment to put the tools.
6. Reduce setup time. Seek to minimize the time it takes to change over a machine to a new size or metal thickness. One contractor had a burn table that could not burn metal fast enough to keep up with demand. By analyzing the setup steps you can increase throughput and avoid the need to run an extra shift.
7. Stop measuring pounds per hour. Measure cycle time, percent of material fabricated right the first time, and the percent the shop delivered as promised. These are better measures for evaluating shop performance.
8. Use “lean” machinery. You want a machine that is easy to run with a quick learning curve for the operators. The less steps the better. We want one that, if possible, does not need watching while it runs so the operator is free to set up the next job, or do another task. The equipment should include signals and mechanisms that will notify the operator of abnormal operations. Operating instructions should include checklists and visual diagrams and pictures to easily show how to operate it. Lean work requires flexibility to move equipment around to meet the ever-changing product requirements. We may not be able to move the plasma cutter, but may be able to move other ductwork fabrication machines. The ease of moving equipment should be considered.
9. Clean is keen. Make sure equipment is properly maintained and operated correctly, so each functions when needed.
10. Buy lean. Do research to determine if the equipment you want is built by a company that is implementing lean. If so, that company is more likely to meet its commitments for on-time delivery, quality and performance. All salespeople will likely claim they deliver quality products on time, but not all do. Look at the install requirements. No matter who does the installation and startup, the process should be user friendly.
10 ½. Go and see. Before buying more equipment to replace the current machinery or to add capacity, go watch how work is done in the shop. Take time to really observe how the work is performed. See how, or if, it flows. Look for bottlenecks and batches piles on the floor or on carts. Watch for workers treasure hunting. Observe how well the equipment is maintained and used, and how material and tools are stored and moved. Don’t just watch one time, but do it over several days and weeks.
Use a “spaghetti” chart to map the flow of various products. Ask lots of “why” questions, never placing blame. In lean we say, “Go and see, show respect, ask questions and do no harm.”
Doing this with an inquisitive mind while looking through lean glasses will give you many improvement ideas without having to spend capital.
Sheet metal forming shops can be much more productive by doing these suggestions instead of just buying the hottest new machine on the market. Lean improves how you do the work, adds value to customers and reduces wasted resources.
Dennis Sowards is an industry consultant and guest writer for Snips magazine. He is the author of the Lean Construction Pocket Guide: Ideas and Tools for Applying Lean in Construction. His company is Quality Support Services Inc. Reach him at dennis@YourQSS.com or at (480) 835-6048.
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