Greater quality. Better productivity. Reduced costs. Each outcome supports the concept of “going lean.”
Lean initiatives provide the insight to resolve inefficiencies, offering companies the opportunity to establish best practices and drive continuous improvement through every aspect of a fabrication or manufacturing business.
Initiating lean concepts, however, doesn’t happen in isolation — and no business is perfect. Any time one change is made to improve one area, it inevitably reveals shortcomings in the current practices in other areas. The welding operation is no exemption. Changes made to increase efficiencies upstream can (and typically will) expose bottlenecks before, during and after the welding process.
When contemplating a newer, leaner approach to producing products, mapping out the entire process is, therefore, critical. Owners, management and team champions overseeing these activities need to look at the whole of the business — from the sales cycle to the manufacture and fabrication of parts and welding, along with packaging and delivery. Every aspect is connected.
Looking at the business side of lean
Implementing lean practices in the welding operation is often a matter of “backing” into the process — looking for ways outside the production area to improve component quality, streamline parts handling and/or improve workflow, followed by an investigation into the impact these activities have on the welding operation. In fact, for vertically integrated companies (such as an OEM) where welding is a small part of a much larger business, it may be best to leave the welding operation as the last point of change during the lean process, as there are many other aspects of the business impacting its success. In addition, the welding operation often presents more complex challenges to address based on the technology used there.
Before altering any part of the welding operation, there are some important aspects to consider. These include:
- The mix and volume of the welding operation — Low-mix, high-volume operations are often easier to streamline than high-mix, low-volume operations that will likely require special compensation due to the overall variation in the applications. Companies will need to plan accordingly.
- Establishing a baseline — Look at the current level of productivity, quality and cost of the welding operation, recognizing that some aspects will undoubtedly be easier to improve than others.
- Available resources — Select champions to oversee the implementation of lean practices in the welding operation. These can include outside resources, as well as those closest to the operation, such as the welding supervisors.
- Committing to a plan — Once resources are in place, companies should be prepared to draft a written plan that provides an overview of the existing welding operation, the recommended changes and goals.
From a business perspective, it is important to recognize that there is no “one-size-fits-all” solution to making a welding operation leaner, nor is there a set time for putting the process in order and realizing the benefits. Those involved in the process must be committed to working toward the common goal of improvement, understanding that the task will take time — some lean initiatives in the welding operation can take months or years to come to fruition, depending on how large the project is.
Committing to ongoing problem solving and a positive attitude is key, as is backfilling work responsibilities for those leading the movement toward lean; it could be very draining on a welding supervisor, for example, to continue overseeing his or her duties while spearheading the lean projects, too.
To gain firsthand insight, engage those working in the weld cell. Welding operators can be the most valuable resources when it comes to understanding the welding process. Ask questions:
- What is the daily input in the welding operation?
- What area needs improvement?
- Could something change to speed up production?
- Are parts more difficult to weld now than in the past? (This would indicate a potential sourcing issue.)
It is equally important to ask “What is working well?” as no company should make a change just for the sake of change. Rather, those leading the efforts can integrate the positives of the current welding operation into future goals.
Standardizing and streamlining the process
As part of implementing lean practices, companies should look at the entire welding operation — pre-weld, weld and post-weld — for opportunities for improvement.
Choosing the right welding equipment and process are good first steps to making the welding operation more efficient. If the existing welding operation produces parts with excessive spatter, for example, it may be worthwhile to consider a process change. For instance, switching from a straight constant voltage (CV) process to an advanced process — such as modified short circuit, which is more forgiving to variations in weld angle and stickout — can help improve weld quality.
Additionally, training throughout the operation should be considered non-negotiable at this juncture and can be carried out through technological or manual means.
For example, advanced welding information management systems integrated into the welding power source can help lean initiatives by standardizing work procedures. These systems can display part numbers to help the welding operator verify the correct parts for the job, guide him or her through the process of loading fixtures and tack welding the part, and allow for the identification and correction of potential tolerance issues. Among other benefits, these systems also provide weld sequencing to guide the welding operator step-by-step through the proper order and placement of welds, which helps control heat input, prevent missed welds and ensure the correct number of welds have been completed. The systems can also help prevent instances of over- and under-welding, and control weld parameters so the welding operation can turn out higher quality welds more efficiently. They can also offer post-welding instructions such as proper inspection, unloading and cleaning of parts.
As an alternative to these systems, companies can offer welding training as part of lean initiatives and provide written work instructions to be posted in the appropriate areas in the weld cell as guidance for the work procedure.
Organizing and optimizing the weld cell
The weld cell layout is important to consider during the implementation of lean. As in other areas of the production process, the welding operator should have the right resources in the right place, whether in the pre-weld, weld or post-weld areas of the operation. Equipment should be easy to access, allowing the welding operator to minimize movement within the weld cell. It is equally important that upstream practices are flowing smoothly into the weld cell to ensure the availability of the proper type and quantity of parts for the welding application.
For companies that weld a variety of materials, it may be worthwhile to introduce multiprocess power sources as part of the lean initiatives. Having the flexibility to weld on a variety of applications without needing to change over the equipment can improve efficiencies. Employing movable equipment (e.g., power sources with running gear) to allow for easy changes to the configuration of the weld cell layout can also be beneficial. Other considerations to support lean practices in the weld cell include:
- Booms for wire feeders to maximize space and reach, and support smooth workflow.
- Welding guns with interchangeable necks to minimize downtime for gun changeover for new applications.
- Fume extraction solutions that maximize space, while also providing adequate ventilation.
- The use of an appropriate-sized filler metal package to expedite spool and/or drum changeover.
- Standardization on a single diameter of wire, when possible, and determining appropriate high and low weld settings to eliminate guesswork about which product and setting to use.
- Indirect supply systems (e.g., vending machines) to monitor contact tip usage and to help reduce instances of excessive contact tip changeover.
Simplifying the number of vendors for welding equipment can also be an important part of making the weld cell leaner — fewer orders, less paperwork and less inventory allows for time and labor to be deployed elsewhere to improve throughput. Companies should also consider a preventive maintenance program for the welding equipment (welding guns included) as a means to help reduce unnecessary downtime to address problems.
Following through for success
When implemented correctly, lean practices in the welding operation can help companies expand their capacity without expanding their facility or workforce. In many cases, they will be able to increase margin contributions, and gain greater competencies to increase profits and competitiveness.
Companies need to remember, however, that improving the welding operation is an ongoing process, rather than an event. Once implemented, lean practices need monitoring to determine their effectiveness and adjusting to ensure they are providing the desired outcome. Patience is important, but so is vigilance — give enough time for potential obstacles to work themselves out, but not so long that potential inefficiencies become integrated into the new welding operation.
Ownership of the lean process is also key. Work with those closest to the welding operation to understand the legacy of the situation — marrying identified benefits to new, positive changes can yield results to drive improvements and gain the best results.