How Does Lean Apply In a Job Shop?
Dear Gemba Coach,
In our job shop we make high precision modules and tools, work that involves a great deal of variety and very little repetition of products or processes. How can we apply lean principles in an environment like ours?
Thank you for that question. Many people I meet assume that lean can only be useful in high volume situations. This misconception is particularly interesting when you consider that many lean techniques were developed by Toyota when the company was in fact a job shop that was evolving into a full-blown mass production model. One of the questions that has obsessed Toyota over the years is how to avoid "big company disease". Toyota leaders constantly ask themselves how they can retain entrepreneurship and artisanship while becoming a massive global player. As we can tell from the news, this question is still as valid now as when it was first asked.
The roots of lean were sown in the workshops of Henry Ford, who had the brilliant idea to transform the nature of automobile production - away from artisans and into something entirely new. His first breakthrough was in standardizing parts (through better precision machining and processing), which eliminated the need for skilled workmen to refine each individual part so that they could fit together in assembly. Ford also broke work down to the smallest possible work component, eliminating the need for skill in the assembly operation itself. He is quoted as complaining: "why is it every time I ask for a pair of hands, they come with a brain?" Many managers today still assume that if a process in a mass production system is detailed and standardized enough, they can put anyone on the job - and then give the customer what comes out. As customers we know better: we deal with the consequences every day that we try to talk to someone on a help line where the people can’t actually do anything for us because they are tied to a narrow scripted response.
So here's the conundrum. The strength of an artisanship approach is the ability to produce one-off products with great care, and to be responsive to every customer's unique requirements. The problem is that this diligence costs a great deal- artisans consider rework as a necessary component of quality and deadlines as lesser concerns to getting it right. And so artisans often price themselves out of the market, losing consumers to cheaper mass produced goods or services. Only in the luxury segment can excellent artisans make a living without having to improve drastically their efficiency. On the other hand, mass production operations could benefit greatly from the care artisans give to their work.
The Best of Both
Ideally, lean operations aspire to occupy the space bridging these two approaches. On the one hand, they seek to retain the cost benefits of mass production in aspects such as line assembly at a regular pace, with work content close to one minute enabling standardized repetitive cycles, producing parts that are perfectly ready for assembly. Yet this system also needs operators with the ability to maintain care for the product. A robot can assemble a car door, but it will never care about the feel of a door closing well. It can never experience that sense of satisfaction a customer feels when a door closes just right or a seat positions itself at just the right angle. It takes an enormous amount of work to find that sweet spot in the Gemba. It requires a lot of training and the kind of team structure and andon mechanisms where operators are taught to develop this fine tuned judgment on parts and the ability to spot when things don’t feel right and work with the rest of the team and frontline management to get the situation back into standard.
Your challenge is to make artisans more efficient without forcing them to adopt techniques that will lower the quality of their work and piss them off in the process. To visualize your Gemba, I am going to imagine your job shop designs dies for specific parts. Your work has two essential components: one is the design cycle, and two is the production of the die cycle. Both cycles are deeply interlinked, but typically, the flow will be broken down between specialists (the engineer, the miller, the grinder, etc.). Flow integration is typically done through an ERP that mixes and matches information about customer demands, component availability, standard times and machine capacity to come up with job orders and a schedule. And then people do the work as best they can, following production orders produced by the computer system.
In a craft culture like this you must work with people to improve their effectiveness. Forcing any new way to organize work on them will backfire in more ways than one - employee resistance, spotty customer deliver, and battered quality. Therefore your first priority should be to formulate a common project. Establish a clear breakthrough challenge that every one agrees to. In job shops, reducing lead-time is a good place to start. Engineers know that providing new dies to customers quicker pays big dividends; shop operators understand that turning out molds faster will increase throughput and reduce backlog.
It's About Time
A good place to start in terms of a lean exercise is to figure out your particular takt time (operating time divided by production requirement). Determining this metric, making it explicit and commonly understood helps everyone shift from a mentality of "we'll deliver when we're done" to a commitment to a steady rhythm of delivery to fulfill customer demand. At first, many people will find takt time a natural fit. But as you do this exercise you'll find that it will focus people on the right time measure. By figuring out a way to apply takt time, you'll have a better understanding of your capacity, which is usually a problem in job shops. After people have accepted and calculated their takt, the next step is make it visible at every step of the process so that people can know at all times whether they're ahead or late compared to the takt.
The next big challenge is to get everyone - engineers and operators - to agree that rework is costly, unnecessary, and should not be a regular part of doing quality work. Everyone should simply assume that they know how to do their work, and should deliver what the customer ordered the first time. This means investigating every time that the shop fails to deliver right-first-time. Making this a regular practice can start with visual boards that are set up across the offices. People are then trained to spot problems, with the goal of creating a system of continuous self-examination. Every time rework occurs, people need to write what happened, what they believe the cause is, what can be done about it, by whom for when. People will balk at having to write all this, which means explaining that this is about confirmation: writing it down allows us to commit to our explanation and share this explanation with others as a starter to teamwork.
Once you've got a steady rhythm of delivery visualized and the confirmation boards in place, you can focus on recurring issues. The trick here is to get every operator to define the good conditions in which to work (work standards); and to elaborate how they go about any job in a sequence of steps (standardized work). This may provoke hard feelings in a craft culture where people are proud of their way of working - asking for standards may threaten what they feel distinguishes them from their co-workers. Explain that standards are not the enemy of, but in fact the baseline for, creativity. It's imperative to work with them to formulate their personal working standards, get them to questions all situations in which they don’t follow their personal working standards, which gets them to share their working standards, compare, and progressively create common standards.
Share Problems, Not Skills
The next challenge is creating teamwork between specialists. Try these two simple techniques. First, a "walk through, talk through" preparation session at the beginning of all the new jobs - having folks anticipate anything we think will not go smoothly. The idea is to get engineers and operators together, to talk about how the work is going to be done in a step-by-step manner, in order to list all potential problems, highlight the large ones, and solve them before starting to machine parts. The second practice is to establish a mid-term plan of cross-training. The aim here is not to develop true multi-skilling. Engineers will never become proficient machinists. The idea is for people to practice each other's job sufficiently to understand the difficulties they create for each other. What we aim to do is to share problems, not skills. In doing so, we can progressively focus on:
- work flow - the logical sequences of steps across the entire job
- Methods to get to repeatable process steps and machine processes
- Regular lengths of time allowed for each process steps according to the takt rhythm.
Remember that the workforce determines the success or failure of the business in a job shop far more than in a mass production setting: it's about the people, not the machinery. They have the common sense and experience to recognize when something isn't right and fix it. They can think and solve problems. They have pride in their work and bring insight to their jobs every day - if they are asked. Improvement can be started at any point if management creates an improvement project that all persons can understand and identify with. Then it's a matter of encouraging engineers and operators to practice confirmation and to exchange their difficulties with an open mind, and to get management to listen to people, learn to trust them and to support their improvement efforts.
Craft cultures tend to center around the pride in the final result and the pride in making each item unique. Your challenge is to build this pride in having projects unfold without a single rework step, end-to-end right first time. If your people latch on to this ideal, they will quite naturally realize the waste caused by some of their practices and attitudes, and this spark of kaizen spirit can then be nurtured to develop lean fully in a job shop environment by applying the discipline of continuous lead-time reduction.