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1.0 SIX SIGMA INTRODUCTION
With increasing competition and emerging global markets, the pressure to provide higher quality software and better customer satisfaction has increased, hence increasing workload but necessitating lower costs. Therefore, it is progressively difficult to be a competitive company as there are fewer resources available. Six Sigma can help organizations learn from and excel at the challenges they meet. It is a tactical methodology, which decides the best approach for a given situation or process.
The success of Six Sigma is linked to a set of functional metrics that lead to significant improvements in customer satisfaction and bottom-line benefits. Some employees of a future Six Sigma organization can view Six Sigma quality as a rigorous application of basic and advanced statistical tools throughout an organization. They can also believe that it is a group of statistical components of old Total Quality Management (TQM) programs with the name of “Six Sigma”. Others can regard Six Sigma as a refined version of TQM. Six Sigma emphasizes the knowledge of the organization with established statistical tools to improve both the efficiency and effectiveness of the organization in order to meet customer needs and requirements. Organizations do not necessarily need to use all the measurements described in this project. It is most important to choose the best set of metrics for a situation, metrics that yield insight into a situation or process.
Six Sigma is a business process improvement strategy, which essentially checks that a business is doing what its customers require, that the process employed is the most effective known and that variation is removed from that process to provide significantly improved consistency. Much
of the initial success in the application of Six Sigma was based on developing the applications however, Six Sigma can also be applied in the services and also banking industries.
As clients place a high value on consistent business processes, which have been proven to be efficient, Six Sigma would meet their requirements as it is a proven methodology for delivering consistent incremental improvement of the software process. By reducing process variation, Six Sigma allows the organization to focus on improving process capability and as Sigma levels increase, the cost of poor quality decreases and profitability increases.
The principal purpose of this report is to review the Six Sigma implementation process and emphasize the importance of this methodology in the quality area of how the software has to behave in the real time environment. For this reason, its main framework is based on the description of the Six Sigma process. Then we move on to discuss the significance of Six Sigma, its statistical interpretation, the team members and their responsibilities and some of the benefits and limitations of this methodology then in next stage I will illustrates the implementation process and the tools, which can be used in order to achieve high-quality results and at the last showing the benefits and difficulties that can occur in the implementation process in some published case studies.
SIX SIGMA APPROACHING
2.1. THE ORIGINS OF THE SIX SIGMA METHODOLOGY
Six Sigma started with Motorola when an engineer (Mikel Harry) began to influence the organization by studying the variations in processes as a way to improve them. These variations are known in statistics as standard deviations and are represented by the Greek letter sigma ( σ ). This initiative became a focal point for improving Motorola’s quality. Bob Galvin, the company’s CEO, emphasized not only variation analysis but also the principle of continuous improvement and established the goal of reducing the company defect rate to 3.4 defects per million, which is near perfection.
Lawrence Bossidy, who after a successful career in General Electric transformed Allied Signal, a failing enterprise, into a successful organisation, adopted this initiative. With Bossidy’s help, Allied Signal increased its sales and profits exponentially. This example was followed by Texas Instruments, which achieved the same level of success. During the summer of 1995 Jack Welch, GE’s CEO, discovered the success of this new strategy and initiated an enormous transformation in his firm.
A drive for greater efficiency and the help of Jack Welch transformed GE into a “Six Sigma organisation” with dramatic results in all departments. For example, General Electric Medical Systems introduced a new diagnostic scanner developed with Six Sigma principies with a scan time of 17 seconds (the norm had been 180 seconds). In another division, General Electric Plastics improved one process for increasing production by almost 500 thousand tons, achieving not only a substantial profit but also an important contract with Apple.
2.2. SIX SIGMA DEFINED
In order to introduce a Six Sigma definition it is necessary first to state the meaning of sigma: For a manufacturing process, the sigma capability is a metric, which indicates how well the process is performing. Sigma capability measures the capacity of a process to develop without defects. A defect means an unsatisfied customer. The quality scale of Six Sigma measures the number of sigma’s between the interval defined by the specification limits. The greater the number of Sigma’s between the specification limits the smaller will be the value of Sigma and the lower the number of defects. The difference between the Upper Specification Limit (USL) and the Lower Specification Limit (LSL) is divided by the standard deviation to give the Sigma Level, z. The capability of a process for a Six Sigma Level is two, obtained by dividing the difference between the USL and the LSL by Six Sigma. Figure 1(a) shows a line with negative slope representing the relationship between the standard deviation (sigma) and the number of sigmas between the specification limits. As the sigma value increases, the number of sigmas reduces and vice versa. The relationship between the number of sigmas and the yield (%) is shown in Figure 1(b). It has a positive slope indicating that as the sigma level increases the process yield also increases. Figure 1© shows the relationship between the value of sigma and the number of defects per million. It also has a positive slope, indicating that when sigma increases, the number of defects per million also increases. Figure 1(d) displays a line with a negative slope, which indicates that the number of defects per million decreases, when the yield
(%) increases.
. IMPLEMENTING SIX SIGMA
There are six phases to implementing Six Sigma in an organization. The first normally begins with leader awareness training and a few improvement projects. These should not only focus on manufacturing, because the company will limit itself to traditional quality improvement initiatives, but it is also necessary to recognize improvement opportunities in all key business processes. The second phase is related to establishing good communication with customers, employees, and suppliers. The information obtained from these groups will help the organization to determine a starting point and to eliminate obstacles to achieving the goals. The third phase is based on the training of the team to assure that adequate levels of numeracy are possessed by all employees. In the fourth concerns the development of a framework for continuous process improvement. In the fifth phase is selected the business process to be improved. Six Sigma projects are organized to improve business performance. Lastly, the individual employees and teams who will conduct the Six Sigma projects are chosen.
Eckes [2003] gives three reasons for implementing Six Sigma the first reason for implementing Six Sigma is the arrival of a global economy and new competitors. This create a new, more competitive market and makes enterprises adopt the level of quality that the customer demands. The second is based on total quality. Due to a reduction in demand and an extraordinary increase in the level of cheap offers, which began in the early 1980s in Japan and in the new industrial countries, customers began to require more value for money. The third reason is generally to reduce the cost associated with poor quality. Enterprises want to make more products rather than to make better ones and they prefer control and correct rather than prevent. Six Sigma qualities is one way to achieve value for the enterprise’s expenditure in terms of both money and resources.
In the 1980s, Total Quality Management (TQM) was very popular but its impact has begun to wane. A new methodology was necessary and Six Sigma is emerging as the new way.
Six Sigma focuses on reducing process variation and then on improving process capability and in order to achieve this uses two improvement models based on the PDCA cycle, introduced by Shewhart and applied the first time for Edwards Deming, which describes the logic of data process improvement. The PDCA cycle is based on the next phases:
• Plan: Identify objectives, choose possible solutions, and plan an implementation test.
• Do: Drive to the planned solution.
• Check: compare with the objective.
• Act: Take necessary action to achieve the goals.
The two Six Sigma models, which are used in order to reduce the number of defects and to meet with the customers’ requirements, are DMAIC and DMADV. The Design for Six Sigma process is known as DMADV - Define, Measure, Analyze, Design and Verify. This process is generally used for product design before manufacturing. The DMAIC process is used to refine the manufacturing process through reduction of common cause variation. The DMADV process is designed to remove variation between what the customer wants and what actually was designed. The DMADV methodology should be implemented when a service or product needs to be developed in a company where does not already exist or it does not reach the specific sigma level. The phases of DMADV are:
• Define the project goals and customer deliverables.
• Measure and determine customer needs and requirements.
• Analyze the process to meet the customer needs.
• Design (detailed) the process to meet the customer needs.
• Verify the design performance and ability to meet customer needs.
The fundamental objective of the Six Sigma methodology is the implementation of a measurement strategy that focuses on process improvement and variation reduction through the application of the DMAIC process which as is shown in Figure 3 is based on five cycled phases.
. BENEFITS AND LIMITATIONS OF SIX SIGMA
When Six Sigma is first introduced, opinions in many organizations vary between enormous enthusiasm and skepticism. At the beginning of its application there can be many disappointments, giving rise to adverse comments such as “There is nothing really new in Six Sigma compared with TQM.” “This will not work in our enterprise. We are doing Six Sigma already,” etc.
Some of the benefits of Six Sigma compared to other quality improvement initiatives are according to Anthony [2001]:
Six Sigma strategy focuses on achieving financial benefits beginning from the bottom line of the business. A Six Sigma project can be accepted without the bottom line having been identified and defined.
Six Sigma needs a passionate leadership for its successful deployment. It integrates the human and process elements for improve.
Six Sigma is based on tools and techniques that have to be followed to achieve the goals. Each has its place and reason to be applied to obtain the final objective of the business.
Six Sigma establishes an internal structure within the business, enterprise which leads, deploys, and implements the approach. This usually takes the form of:
1. Master Black Belts (MBBs).
2. Black Belts (BBs).
3. Green Belts (GBs ).
Six Sigma is based on the importance of accurate data and decision making rather than on assumptions. Six Sigma utilizes statistical concepts, tools, and techniques for reducing the number of defects based on variability reduction. Six Sigma like any other quality improvement initiative has its limitations.
Sometimes, there are many problems in applying the change and finding the data to begin with can be difficult. This could take most of the project time. One of the most important problems associated with implementing the Six Sigma methodology is determining the right selection and prioritization of projects. In some enterprises, the process of prioritizations is completely subjective.
The statistical definition of Six Sigma is 3.4 defects per million of opportunities; on the one hand, this can result in dissatisfied customers, but on the other it cannot assume that all defects have the same level of severity. For instance, for an airline company a tragic accident is more serious than a cold meal. A 1.5 sigma shift cannot be assumed for all processes.
Six Sigma can easily digress into a bureaucratic exercise between Master, Black and Green Belts. The relationship between Cost of Poor Quality (COPQ) and Process Sigma Quality Level requires more justification.
Here I have discussed about the necessity of implementing Six Sigma, the role of the different members of the team and some of the benefits and limitations that this methodology imply. The principal objective of the next discussion is to approach, in more detail, to the tools and methods used during the implementation process.
3.0 THE IMPLEMENTATION PROCESS
3.1 PROJECT SELECTION
In order to make a good project selection for Six Sigma application, it is necessary to understand both the organization and the customer.
Before an organization decides to implement the methodology, it is necessary for the Managers to understand the meaning of a Six Sigma organization and what is needed to achieve it. Six Sigma initiatives require a radical change within the organization and a great deal of effort for achieving the fundamental goals. Within an organization, there are a lot of interconnected processes and functions to form the end product. Enterprises produce different products and services all of which are going to be consumed, so they have to be competitive in the marketplace and for this reason should have a good quality-price relationship.
Six Sigma is a methodology for improving existing processes and creating new ones and it provides an excellent opportunity to review and revise corporate strategy plans. Several products, services, and processes may be inappropriate, ineffective, or even inefficient and should be analyzed. Each organization decides what it is going to produce but the product should be made to suit the needs and wishes of the customer. Organizations must be able to recognize the customer and their needs and expectations. The success of a company in the marketplace depends on several factors one of which is quality. If a company is to achieve its goals, it should consider its situation in the market is going to be and use its resources to achieve the required goals. After understanding the products and the services offered, and even the market, the company has to be aware of how quality can be used as a key differentiator. Increasing quality in products and services allows a company to enter newer and wider markets, to consolidate its existing market and to center on customer satisfaction.
When an organizationbegins to grow and develop in size and structure a lot of inadequate and inefficient processes emerge. Most of the employees of a business realize that a change is needed but are unable to carry out improvement. Projects teams, for implementing Six Sigma, need extensive training. The best way to start a project is to define a dynamic document, which sets out the responsibilities, goals, roles, and aims of the team.