Lean manufacturing, lean enterprise, or lean production, often simply, "Lean", is a production practice that considers the expenditure of resources for any goal other than the creation of value for the end customer to be wasteful, and thus a target for elimination. Working from the perspective of the customer who consumes a product or service, "value" is defined as any action or process that a customer would be willing to pay for.
Lean is a management philosophy derived mostly from the Toyota Production System (TPS), and it means that you work with continuous improvements while identifying and eliminating all waste (Muda in Japanese).
With the Lean way of thinking, the company start with their own production processes (products or services) and analyze how best to make them more efficient. The most common questions raised are: What do we know? What are we good at? How can we improve and create value for our customers?
The basic idea is to maximize customer value while minimizing wastes with a minimum of resources as possible.
By looking at the entire value stream from order to the finished delivered product and eliminating non-value-added elements, formed processes that require less human effort, less space, less capital investment and less time. Products / services provided at low cost with high quality assurance in conjunction with traditional business systems.
TPS-temple with vision, main principles, principles and result (source: Petersson, P. et al (2008) Lean – Gör avvikelser till framgång)
Lean principles should be used as a guideline. The principles must in turn be well entrenched in the organization’s values. These values reflect the organization’s preferred desired way of relating to the stakeholders (employees, customers, owners, society). These values permit entire operations and affect the way an organization thinks and operates. This creates the conditions for achieving results that satisfy stakeholders.
Values impact on principles, methods, results (source: Petersson, P. et al (2008) Lean – Gör avvikelser till framgång)
Lean is not only for production and is not a temporary tool or project. Lean is an ongoing process including all functions in a business, which includes from product development to sales, all functions that is adding value to produce a product / goods / services.
It is important that an implementation of Lean is used as an activity for everybody and that the management has a clear targets and support both through self-commitment, accessibility and create the correct circumstances for the organization.
Principles of Lean
The five-step thought process for guiding the implementation of lean techniques is easy to remember, but not always easy to achieve:
- Specify value from the standpoint of the end customer by product family.
- Identify all the steps in the value stream for each product family, eliminating whenever possible those steps that create no value.
- Make the value-creating steps occur in a tight sequence so the product to flow smoothly toward the customer.
- When the flow is introduced, let customers pull value from the next upstream activity.
- When the value is specified, value streams are identified, excess steps are removed, and flow and pull are introduced, restart the process again and continue it until a state of perfection is reached in which perfect value is created with no waste.
Principles of Lean, the five steps (source: www.lean.org)
Lean Tool box
Over the years, a variety of tools and methods has been developed within Lean. We will highlight some of the most frequent and basic tools below;
- 4P: n (Philosophy, Process, People & Partners, Problem Solving), the basic philosophy of unified control and develop their daily work.
- 5S (Sort, Systemize, Shine, Standardize and Sustain) the basic tool to get things cleaned up, organized as one of the first step toward continuous improvements.
- Root Cause analysis, a common approach is to ask why five times – each time moving a step closer to discovering the true underlying problem.
- Kanban and supermarket to establish a pulling system in the flow
- Heijunka for equalization of product variation in the working operations.
Value Stream Mapping (VSM)
Value Stream Mapping is an important tool for identifying problem areas and to design the desired future value stream. It should contain an entire value stream for the product´s / device through measurements of time, work in progress and resource utilization.
A value stream includes all necessary activities from raw material to the finished product. It involves all activities that create value and those that do not add value, but are sometimes necessary when processing a product.
The Lean philosophy is meant that if you fail to use this analysis, there is a risk for isolated improvements with no impact on the value stream to the customer value or the profitability. Consequently, we believe that the problem has been pulled back in the flow. See Figure 8, which shows the symbols used for a value-flow diagram.
Symbol in a Value stream mapping (source: Rother & Shook, 2004)
- Define and pick the product or the product family
- Gather a group with requested knowledge and experience of the processes.
- Brainstorm an initial map of the flow
- To do a current status analysis, collect information such as available time, existing resources, scrapping, availability etc.
- The last step is to start from current state analysis and design a future improved status and propose action plans.
- Continue to follow up the results/process (Continuous improvement)