January 1, 2010
Spending money for equipment is always a challenge for contractors. Everyone wants top value for his or her investment.
Typically contractors compare the cost of the equipment to the projected return. Considerations usually include the capacity and speed of the equipment - more is considered better - maintenance costs and warranties.
Steven L. Streimer, vice president at Streimer Sheet Metal Works Inc. in Portland Ore., says they would look for “one machine for a given purpose that is capable of a broad range of product variants. Such as a spiral machine that produces duct in 28-gauge through 14-gauge materials.”
At Streimer Sheet Metal they have been implementing lean practices in their shop for several years. Lean has changed how they look at everything.
Streimer puts it this way: “Knowing about lean, we now realize our previous decision criteria has been all wrong. Not only have we, in many cases, paid too much for a machine capability which is only used 10 percent of the time, but by doing so we have also handcuffed our ability to streamline the setup process. Looking further at our historical decision criteria, we now know it makes little sense to have a fast machine when the operator has to stand at the machine anyway and could be used for a different task and/or only to have the fast machine now sit idle while the rest of the process gets caught up. We now find ourselves looking for equipment which fits a specific task, has limited setups and fits well within the rest of our value stream.”
CriteriaEspecially when money is so tight these days, contractors who are applying lean principles should incorporate some additional criteria in selecting sheet metal equipment.
Running a shop using lean techniques is a different way of thinking about how work is fabricated.
Lean focuses on product flow in small batches. Lean is often counterintuitive to traditional shop-process thinking. It organizes the work not by function - welding, insulation, etc. - but by product type. Lean tries to eliminate waste, which includes fabricating product too soon, product waiting, movement by people as well as material movement, unnecessary 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 maybe 70 percent to 80 percent capacity or less.
• Building one fitting at a time rather than many fittings in a batch mode.
• Not building products until the field needs it, instead of fabricating duct weeks ahead and stockpiling it at the shop or sending it to the jobsite early.
• Matching the material fabrication to the capacity of the slowest station rather than running each area independently and stockpiling work-in-progress inventory at the next station.
For example, there was once a shop that burned so many jobs and put each on rolling carts that they ran out of the carts. This limited downstream operations that needed the carts, too.
• Focusing on having tools and needed parts at point of use to reduce “treasure hunts.”
• Making sure that equipment is properly maintained and correctly operated so it functions when needed.
• Minimizing the time it takes to change over a tool to a new size or metal thickness, such as a plasma cutter or a large brake machine.
• Not measuring pounds per hour, but 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.
• Separating the operation of a machine from the operator. Watching a machine work is waste. Lean seeks to use machines that can operate autonomously and will signal the operator when the job is done, when a defect is produced, or when any abnormal situation happens.
Consider thisWhen 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 some primary considerations:
Is the equipment built by a company that itself is doing lean? If so, it is more likely to meet its commitments for on-time delivery, quality and performance. All salespeople will claim they can deliver a quality product on time, but not all do.
Look at install requirements including time. No matter who does the installation and startup, the process should be user friendly.
Smaller is better. You don’t need one super machine that can 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.
You want a machine that is easy to run with a quick learning curve for the operators. The less steps the better. You want one that, if possible, does not need watching while it runs so the operator can be setting up the next job or doing another task. The equipment should include signals and mechanisms that will notify the operator of abnormal operations. Operating instructions should include checklists and possibly visual diagrams and pictures to easily show how to run it.
Especially important is to have equipment where setup and change-over can be done in the minimum time with good ergonomics.
The equipment should be easy to maintain, with maintenance instructions clear.
Where possible, you want to use gravity to help. We want to go from a higher level to a lower level to feed the machine, and when taking product off of it when done.
Lean work requires flexibility to move equipment around to meet the ever-changing product requirements. You may not be able to move the plasma cutter around but may be able to move other machines. The ease of moving the equipment should be considered.
Like buying a car that has unique parts or tools that are hard to find and expensive to replace, we want equipment with simple common tools and replacement parts.
To minimize “treasure” hunts, lean seeks to put the tools needed for running or adjusting equipment right on or next to the equipment itself. If the equipment manufacturer is doing lean, the company will understand and design its equipment for this need. If not, look at what tools are needed and if there is space on the equipment to put the tools.
One other interesting approach, not always used by contractors prior to applying lean, is to involve those who use and/or maintain the equipment every day in the decision-making process. This gives trust and ownership to the operators and they in turn look for ways to do lean.
Consider used equipment as a better alternative than purchasing new. Used equipment may be especially useful where the need is low, such as a line of products made less frequently. This could free a better machine for the fabrication of the main product lines.
The last idea, which really should be the considered first is: Do you really need the equipment? A basic lean principle 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 generated through applying such lean tools as the Five S and Kanban, and no new capital equipment is needed.
Dennis Sowards is an industry consultant and author of the research book Thinking Lean - Tools for Decreasing Costs and Increasing Profits, funded and published by the Sheet Metal and Air-Conditioning Contractors’ National Association-affiliated New Horizons Foundation. His company is Quality Support Services Inc. and he can be reached at dennis@YourQSS.com or at (480) 835-1185.
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