Standard Work: The Foundation for Kaizen
Standard work is one of the fundamental disciplines of the Toyota Production System (TPS) and lean manufacturing. Also called standardized work, standard work is key to maintaining stability, solving problems effectively and scientifically, and kaizen (continuous improvement).
Standard Work Definition: the best known and demonstrated method for producing a product or service.
Standard work is essentially a recipe for success. The meaning of the term itself has been blurred over time but has classically been used to refer to the documentation used by Toyota. When used well, this documentation becomes the “sheet music” of production that every operator plays to.
Other formats of standardized work include the following and are discussed below:
- Work instructions & SOPs
- 8 Step process
- One point lesson
- TWI job instruction
Each of these methods has its strengths and weaknesses but the overall goal remains the same: laying a foundation for problem solving and kaizen.
If you are struggling with consistency of operations, effective problem solving, or creating a culture of continuous improvement, part of the problem could be an inadequate or inappropriate use of standard work.
The Foundation for Kaizen
It’s easy to lose focus on the purpose behind standard work. What we’re trying to achieve when applying standard work is a world-class process that sticks. In this context, there are three activities of standardization to “make it stick” and achieve lasting kaizen.
- Stabilize the process – the 4M’s (man, machine, material, and method) must be stable enough to support standardization of work methods. Machine downtime, labor shortages, training gaps, quality issues, variation of methods, etc. must be made stable.
- Standardize the process – once stability is accomplished the best known and demonstrated work method can be standardized. This becomes the baseline for evaluation and future improvement.
- Sustain the process – there’s no point to standardizing the process if the standard isn’t sustained! Management practices and follow-ups must be modified to appropriately sustain the gains achieved by standardization.
It’s important to understand here that every kaizen should result in revised standard work.
As shown above, standardization is the key to making an improvement “stick.” You have to stabilize, standardize, and sustain effectively in order to prevent a process from deteriorating and falling back down the hill of continuous improvement. If you do not learn to practice standardization well, you will struggle with kaizen.
Ultimately, standard work is the foundation for kaizen because it provides a basis for evaluation. There is no way to know whether an improvement is truly an improvement unless there is a standard to compare it against.
It is for this reason that Taiichi Ohno (left), the father of the Toyota Production System, famously said, “Without standards there can be no kaizen.”
It’s All About Creating A Recipe!
Standardizing work is all about creating a recipe. Recipes—just like grandma’s famous chocolate chip cookies—are not intended to limit creativity but instead to perpetuate success and provide a baseline for further improvement. Many of your favorite recipes have probably been perfected over time with experimentation and improvement. The intent of introducing standard work is the same!
A good standard represents the best-known method for accomplishing something. It explains in appropriate detail how to mix and match the following ingredients:
- Work sequence
- Timing of events
- Number of people, machines, and material
- Layout of people, machines, and material
- …and any other relevant information!
Although many companies have SOPs and other forms of work standards, the majority fail to achieve the goal of recipe-writing in a way that is both effective for evaluation and easy to maintain. It is a rare and lean-thinking organization that views standard work as a recipe and gets genuinely excited about it.
Traditional Standard Work
There are three critical requirements for traditional standardized work, such as what is used at Toyota and other organizations.
- Takt Time – this is the time required for producing a unit and is matched to customer demand. It is standardized so as to prevent the worst of all wastes: over production!
- Work Sequence – this is the exact sequence of steps taken to complete the work.
- Standard Inventory – this is another control that helps to coordinate all operators and machines involved in the work and also limit over production.
Developing the standard for these three elements usually follows a defined methodology involving the completion of time studies and related worksheets. The number, method, and sequence of worksheets can vary between organizations but often includes the following examples.
Warning: although this is the “traditional” way of creating standard work, there are innovative alternatives that may also work well for you. (These are discussed in the next section).
Process Capacity Sheet
Time Observation Sheet
Standard Work Combination Table
Standard Work Instruction Sheet
Other worksheets may be used to develop the standard, but these four represent some of the more common worksheets used in industry.
TWI Job Instruction
In many organizations Training Within Industry (TWI) Job Instruction represents the “next step” after defining a process via traditional standard work methods described above. This job instruction documentation functions like a well-crafted training document.
Job instruction in this manner dates back to World War II. The United States developed TWI to train over 1.6 million workers to help in the war effort–which is nothing short of astounding! After the war, Toyota learned it from the Americans and TWI became embedded in the Toyota Production System. Ironically, the United States largely forgot about TWI in industry until many decades later.
Job Instruction encompasses both the training method followed by trainers and the structure of the training documentation, which is a form of standard work. This documentation is often called a “Job Breakdown Sheet.”
Job Breakdown Sheet
The Job Breakdown Sheet has three major components that are used to document and standardize the task. The standard is a training aid and is not self-explaining.
- Important Steps – the “what” of the job
- Key Points – the “how” of the major step
- Reasoning – the “why” of the method/key points required
Trainer’s 4-Step Process
Trainers who follow the TWI Job Instruction method follow a prescribed training model of four steps. Although at-a-glance this model appears easy to understand, these four steps are very specific and require disciplined execution. The original certifying course for TWI job instuctors is a 10-hour course!
The Four Steps:
- Prepare the worker
- Present the operation
- Try out performance
- Follow up
Alternative Forms of Standard Work
There are indeed other ways to document and use standard work! Check out some of these alternative methods.
Video (FastCap Example)
8 Step Process
SOPs and Work Instructions
One Point Lesson
Creating The Documentation Is The Easy Part!
Just because you can create documentation doesn’t mean that it’s going to be used effectively. This is where many well-intentioned lean or ISO programs fall short. You have to sustain it!
Sustaining standardization occurs when you change the management system to appropriately own the documentation and follow-up on current practices on a regular basis.
Here’s some tips to do just that:
- Teach that standards are recipes and that everyone is expected to follow them and improve them.
- Push the work of standardization as far down as possible: to the level of frontline team leaders and supervisors.
- Make it easy to create and update the standards. Limit bureaucracy! Think photocopy and pencil (if possible)!
- Develop team leaders as trainers, auditors, and problem-solvers for the sake of improving the standards.
If you don’t also change the practices of your management system, your documentation will quickly become out of date and begin collecting dust!