October 25, 2011
While lean manufacturing was developed for the continuous, automobile assembly line environment, it can work for architectural sheet metal fabricators, too.
Lean thinking will help the architectural sheet metal contractor be more competitive and successful.
An important principle of lean is to focus on the three priorities for managing work. They are:
• Protect the customer. Customers are paying for a completed architectural job that meets their requirements and expectations. For the fabrication shop, the install crew is the next-in-line customer. The crew is the most expensive per-hour work unit and should always be installing value-added work. All support functions and efforts should be focused on this priority - keep the crews doing value added work. This means you don’t want to gain efficiency in the shop that creates greater work in the field install area, even if you are not the installer.
• Reduce inventory. Because of the hidden costs of inventory, you want to reduce work in progress and inventory as much as possible without impacting priority No. 1.
• Reduce other costs. Any way to save money in how you purchase, store and ship parts and material, and in covering administrative costs, helps profitability - as long as it does not interfere with the No. 1 priority.
These three priorities seem straightforward, but there are many examples where managers have them reversed. Lean thinking starts with understanding what is value and waste and the priorities of managing the work.
Here are eight ways to apply lean in the architectural sheet metal shop.
1. Do value-stream analysisBecause each architectural project is unique the lean approach is to look at the value stream (the process steps from design to install). This is also called a “kaizen” event. (Kaizen is Japanese for “continuous improvement.”) A team including the design, fabrication, assembly, and install people will be involved. The team maps out each step of the value stream looking for ways to deliver greater “value,” as seen by the customer, and to eliminate waste as defined through lean.
There are seven basic types of waste. While doing the value-stream analysis, the team will especially look for duplicate, redundant, and other non-value-added steps. An assessment of potential safety and other risk impacts may be part of the analysis.
2. Modularize the workDon’t just fabricate pieces but try to assemble as much as possible in the shop before shipping to the job. Build it as big as you can ship and safely install it. This may mean bringing other trades into the shop or doing some of their work such as installing lighting or siding while the module is still on the ground. Much time can be saved with assembling in the shop, not to mention the improved safety factor.
3. Seek flowLike any lean effort, you want to make sure to deliver the job on time for the customer, yet you don’t want to make or install anything too soon. This means short lead times. Improving lead time requires a focus on creating continuous or near-continuous fabricated product flow. Flow will also help identify problems quicker. This can improve quality - another customer requirement. With continuous flow, quicker communication between steps is needed because you can’t hide the problems in the large batches. Flow facilitates increased productivity and conserves resources.
Where the product can’t flow continuously from one step to the next, use the next-best way to “pull” to the next. Pull means don’t make or send it to the next step until that step is ready. Contractors often push product through by cutting all pieces for the job at one time. They then batch load the pieces and move them to the next step. This way they are pushing it downstream.
You want to create a near-continuous flow from start to finish. We want “FIFO” (first in, first out). Don’t start fabricating a product until everything is in place to finish that piece before starting the next.
Often what happens is material is sheared and then waits on a rolling table for several days. This table may even get moved several times during a day. Finally, the items are processed days later. Do not start a piece only to have to stop while waiting for something else to happen. To get the best flow possible, think through the flow of the job, and walk through it in the shop, to identify ways to move product from one tool/step to the next.
4. Produce quality workDoing quality work, right the first time, is always important. The visible and the often unique aspects of this type of architectural sheet metal necessitate addressing quality on many different levels. Quality is conformance to valid requirements that may include requirements for finish, fit, etc., as well as the customer’s use requirements.
One way lean addresses this is summarized in the statement about poor quality: “Don’t get it. Don’t make it. Don’t send it.” If someone receives bad-quality designs, metal or other defects, he or she needs to work with the previous supplier to get it done right the first time.
Never do work-arounds. The worker must know what is “right” in receiving upstream work; what “done right” is to make the correct piece; and what “right” is to pass completed work downstream.
5. Organize the workplaceReduce “treasure hunts” in the shop. When workers are walking around looking for stuff they are not adding value. Use the lean tools of “Five S” and “kanban” to minimize the hunting. Workers should carry frequently used tools such as tape measures and box cutters on a tool belt. Locate other tools close to where it is frequently used. There is much wasted time in shops as workers search for what they need to do the job.
6. Use pull planningA very useful job-planning tool is “pull” or reverse planning. After making improvements in the value stream (see value-stream analysis) starting with the last step, work backwards, step to step, identifying the hand-off requirements and time to do each step. Any special schedule and quality issues are also identified. Representatives, from the trades doing the install, need to be involved in this event. As the team works backward through the steps there is meaningful discussion about the hand-offs, best install sequence and possible problems.
Done correctly, pull planning increases collaboration and eliminates many communication problems and false assumptions typical of most construction jobs.
7. Involve workersShop and field supervisors and other workers need to be engaged in doing lean. Engagement comes through teaching lean principles and tools, and asking workers what they think can be improved. Management must listen to employee ideas and take action where possible.
Management should discuss each job’s requirements and delivery dates with the workers so they buy into the priorities. Doing a “walk through, talk through” with employees before starting any job will improve productivity. Teach employees problem-solving skills so they will seek the root cause of problems in a systematic and effective way.
8. Lean is learningBecause most architectural jobs are unique, contractors usually have not done any like it before. This means they need three types of learning to be successful:
• Learn from the past. While you haven’t even done this job before, in many cases you have done similar jobs. Lean contractors will have a system of documenting key techniques and lessons learned on all jobs for future reference. Non-lean companies will rely on the memory and experience of its workers. This can help as long as it didn’t downsize the workers and they remember the key points years later.
• Learn from the field. All fabrication and module assembly must be field-install “friendly” or contractors lose the advantage they hoped to achieve. Early in the design process involve the field people who will be doing the install and fabrication process so it works for them and they know the install plan.
• Learn fast. As the field starts installing, there can be additional improvements made to the process. The lean principle of “go and see” means that management and engineers need to go to the worksite and watch how the install is being done. Look for barriers to the installation workflow. Look for ways to reduce treasure hunts for material, parts, tools and even information. Look for bottlenecks and communication breakdowns. Go and watch; then be flexible and experiment. Try better ways.
Lean is also about experimentation; trying new ways and learning what works better and what doesn’t. Architectural sheet metal is challenging work by its very nature, but lean will make the company better.
Dennis Sowards is an industry consultant and guest writer for Snips. His company is Quality Support Services Inc. He can be reached at dennis@YourQSS.com or (480) 835-1185.