The concept of quality has changed over time. The awareness about quality started in the early half of the twentieth century but back then quality was considered more of a technical issue and the onus of quality was vested in a department, which was called quality control department. As the name of the department suggests; quality was a control issue, and hence statistical quality control techniques were developed to keep a ‘control’ over the quality. However, with time and with Japanese influence, this concept has changed.
Now, quality ownership is not vested with one department only but with the entire organization. Everybody in the organization is now quality conscious and quality has become more of a managerial and cultural issue rather than being just a narrow technical one. This transformation of the narrow concept of quality management over time into an all-encompassing broad concept of quality in everything and for everyone has been brought about by the concept of total quality management. In short, total quality management means quality for everyone, in everything and by everybody in the entire organization. It is a much broader concept and views quality more as a management issue than a technical one.
Most importantly, TQM is a continuous process and must be viewed as a process of perpetual improvement to improve the quality of about anything in the organization. It focuses on getting things done right in the first attempt and is more of a philosophy of working (attitude towards working), than anything else. The concept is not new and has been in use in Japanese companies from the mid 1950s, but has gained acceptance in the West from 1980s onwards. TQM has some principles that if adhered to in designing management strategies and processes will result in total quality within the organization.
We’ll be covering the following topics in this tutorial:
The Principles of TQM
The principles of TQM are as follows:
- Quality can be managed and requires management will to be managed. Itis an extremely important ingredient of successful management.
- Everyone in an organization has a customer.
- People are not the main problem for quality but processes are.
- Everyone is responsible for quality. The ownership of quality is vested in each employee.
- Problems must be anticipated and with proactive decisions, prevented not merely solved.
- Quality must be measured in understandable terms (preferably in quantitative terms).
- Improvements in quality are itself a continuous process and must not be viewed as frozen in time.
- Zero defects or six sigma should be the quality standard.
- Goals once defined on the basis of known requirements are not negotiable.
- One must always measure lifetime costs instead of upfront costs.
- Management must be completely involved with quality management and should lead the effort. There should be complete buy in at the top management level.
- Quality management initiative must be a planned and organized effort.
Six Sigma is a method used for measuring, improving and controlling process performance. A methodology, which improves customer satisfaction significantly, by reduction of variation in the processes.
‘Six Sigma is not something else that you do … it is what you do.’
What is six sigma?
- It is a philosophy which results in operational excellence.
- It reduces variation in processes and operations.
- A statistical measure of a process capability – 3.4 defects per million opportunity _ 99.99966 per cent probability of passing non-defective products to customer.
Benefits of six sigma
- Increased customer satisfaction
- Reduced defects
- Increased productivity
- Better and consistent processes
Six Sigma Methodologies
For Existing Processes (DMAIC):
For new design and new processes (DMADV/DFSS):
Organizations implementing six sigma
Six sigma has been successfully implemented by manufacturing organizations like GE, AT&T, Motorola, Honeywell, etc., service organizations like American Express, IBM, Accenture, Microsoft, J.P. Morgan Chase, to name a few.
Six sigma approach
Where, Y = Output or Effect
X = Input or Cause
The define phase focuses on customer feedback or VOC (voice of customer). It is important to understand who the customer is and then understand the customer requirements. There are tools like interview, survey, focus group, etc., used to collect customer requirements. Once the VOC is obtained, it is translated into a measurable metric called the CTQ (critical to quality). A CTQ should be SMART (Simple, Measurable, Attainable, Relevant and Time bound).
The next step in define phase is to create the six sigma project charter. This is similar to a project plan and has six mandatory sections:
- Business case
- Problem statement
- Goal statement
- Timelines or milestones
Any six sigma initiative consists of customer, sponsor (who finances the project), project champion (the subject matter expert), six sigma team (master black belt, black belt, green belt) and team members (who help in the project).
The last deliverable in define phase is creation of a high-level process map or IPOC.
SIPOC =Supplier – Input – Process – Output – Customer GE uses COPIS:
COPIS = Customer – Output – Process – Input – Supplier
The following activities are undertaken as part of measure phase:
- Defining performance standards – consists of the target and the specification limits (operating range on the target)
- Data collection – data is collected for all potential causes
- Data analysis
- Measurement system analysis – no process can be completely variation free. In the measure phase, we call this the measurement system analysis. In a six sigma project before we start analyzing data, we have to ensure that the measurement system does not contribute errors of its own due to person measuring, or the measuring instrument or the sample that is getting measured
- Process capability – it is the measure of the current state of the process
The following activities are undertaken as part of analyze phase:
- Basic data analysis on Y
- Identifying all potential causes, which are called ‘Trivial Many X’s’
- Finding out the root causes or ‘Vital Few Causes’ – tools such as fish bone diagram, Pareto analysis, cause and effect matrix, etc., are used to separate the vital few from the trivial many
- Validation of root causes
After the previous phases, we have a set of validated X’s. The deliverables in improve phase are:
- Design solutions – when X’s are isolated and independent, tools such as brainstorming, lateral thinking and TRIZ are used to design solutions. When X’s are interdependent, DOE (design of experiments) is a method used for conducting controlled experiments of how a process performs under differing conditions of variables
- Risk assessment – failure mode and effects analysis (FMEA) evaluates the different ways an input to a process step can fail and tries to understand the cause of that failure
- Solution Implementation
- Solution validation – used to measure the success of the process. Cost benefit analysis is used for the same.
Control phase attempts to find out the stability of the process and ensures sustainability. Every completed six sigma project should have not only a control chart but also a control plan. This ensures that the process does not revert to the way it previously operated.