Constructing a Stable Lean House

Christi Beck-Levicki Blog

Part II of a blog series that focuses on implementing a Lean system and what Saline Lectronics is doing to guarantee a successful, Lean implementation.

A. Implementing a system by building a strong foundation

As described in the previous post, How to Avoid the Pitfalls of Lean Implementation, Lean is a system that is most successful when all parts of the business are working together simultaneously to achieve exponential improvements. To build an effective Lean system there must be a strong and stable foundation.  To achieve this, all employees are engaged in problem solving (Kaizen), and are united behind the goals of the company. Standard work is another critical element to providing a consistent foundation. When all employees follow a standard process it eliminates the wide variance in process steps, and keeps the factory flowing smoothly, while still avoiding possible safety, quality and delivery issues. Once there is a strong, stable foundation the other parts of the house can be put in place.

IMG_9677

Lectronics’ technicians perform mechanical assembly on a lean flow line.

B. Building the Lean House, putting up the walls

The main supporting pillars of the Toyota Production System House have been described many different ways but put simply are; Flow and Quality.

Flow, (sometimes referred to as Just in Time, (JIT), Continuous Flow) is a lean concept where product moves swiftly through the various process steps; it is triggered by a pull from a customer generated order.

Flow starts when an order is first received by the sales office. It’s essential that Lean is applied to all aspects of manufacturing including administration, because many times this process is plagued with waste, but as this waste is not as easy to see, it is therefore often ignored. Sometimes the upfront work to get an order to the production floor is more difficult to accomplish than the actual manufacturing process as it tends to sit waiting on information, approvals, or the next operation. If the office process does not flow, valuable time is wasted which then reduces the time manufacturing has to process their portion of the order.

At Lectronics, we have office-focused Kaizen teams to review each step from the quoting process to physically entering a customer order into the system. The subject experts work together to identify waste in the process and how to best eliminate it. Several internal processes have been totally revamped and streamlined at Lectronics allowing for waste to be dramatically reduced, resulting in faster delivery of product to the customer.

The production process is where most of the lean effort is typically placed. Great strides can be made by breaking down batch sizes to smaller, more manageable quantities, and striving for One Piece Flow wherever possible. Being able to identify and measure the waste is critical in reducing or eliminating it, with many companies ignoring the biggest waste due to it being too challenging and difficult to streamline.

In Electronic Contract Manufacturing, moving the customer’s product through the manufacturing process as quickly as possible is key for meeting a customer’s delivery schedule. Getting the product to flow through each process step can be difficult when assembling so many different types of products with various cycle times. Applying lean flow techniques, such as balanced work and lean cell design, allows products to be built on flexible lines. These cells are designed to level the workload between operations, with the goal of reducing work in progress (WIP). With balanced work between operations, limited WIP, and the ability to change models quickly, parts can flow through the process seamlessly enabling production to meet daily shipping requirements, while still quickly reacting to  changes in the schedule.

Lectronics recently revamped the mechanical assembly production process from being assembled on a bench to flowing in-line. This Flow change has reduced WIP, and improved delivery commitments to the customer. In fact, Production is now able to take on higher volumes while still turning products faster and more efficiently.

Quality systems have been described in many different ways; for Lean, the key to a Quality system is build it right the first time. Many ECM’s tend to avoid addressing product and manufacturing issues assuming that they can be fixed later. This philosophy not only leads to an enormous amount of repair work, but also creates other quality issues related to repair and assembly flow. Ignoring issues severely impacts the flow of parts and causes key delivery metrics to be missed.

Mistake Proof, (Poke Yoke)There are several key lean tools that support the philosophy of building it right the first time. One of these is the concept of mistake proofing, or Poke Yoke, which can be built into each automatic or manual process operation. When this lean tool is implemented properly, it completely prevents an operator or an automatic station from building a product incorrectly, thus preventing quality issues from ever taking place. In the highest level Poke Yoke system, parts cannot be manufactured wrong. While it can be both impractical and cost prohibitive to build-in the highest level of Poke Yoke, intermediate level Poke Yoke is preferred and is better suited for a manufacturing process. An example of an intermediate Poke Yoke would be a situation where if a part is built incorrectly, the operator is alerted of the error and the part is also locked so it can’t be moved to the next operation.

With the implementation of flow lines at Lectronics, the Poke Yoke concept is designed into each operation step.  As parts flow one piece at a time, if an issue arises the Poke Yoke serves as the stopping mechanism that prevents the part from moving to the next operation.

Standard Work:  Another key lean quality tool is Standard Work. Automatic stations, (pick and place, paste inspection, etc.) can be programmed to acceptable quality tolerance limits and repeat process steps consistently and accurately. To control variation of automatic stations, designing Standard Work is paramount. In an automatic station, as long as the equipment is maintained and accurately calibrated for the work that needs to be performed, the equipment will build a quality part each and every time. Automatic stations can improve the consistency of product assembly if the automation is intentionally designed and properly applied. Some companies see automation as the silver bullet solution and misapply automation with parts of an operation that should be performed by a human. This misapplication not only burns up critical resources for de-bugging, but can also lead to poor quality. Once an automation station makes an error it tends to keep making that same error until it is actually noticed and stopped.

Manual stations are dependent on the Operator controlling the work performed and ensuring that the same process is done each and every time. If a process is not well defined, or has too many difficult steps, or is physically straining, operators will find the easiest method to accomplish the required work. While the easier process method may be easier for the operator, it can also violate important quality steps that are necessary to the process. Developing Standard Work with clearly defined operator work instructions is essential to building in quality. Additionally, working with the Operators to define the best method of assembly, right balance of speed and correct ergonomics is critical to creating Standard Work. Once these tasks are defined, documenting the Standard Work in a very simple, visual format is paramount. It is essential that operators are not only able to perform this required task, but are also able to move from different positions within the lean cell to promote flexibility.

Overall, creating stability through effective management of Quality and Flow coupled with a culture that values continuous improvement will generate a truly unique Lean House – a type of building so strong and resilient that it can weather any storm while still accelerating business growth. Next Blog Post will focus on the bond that holds the entire house together – the people!