Although Six Sigma methods focus on improving a company’s bottom line, there are many problems associated with this quality improvement philosophy: the large investment of time and money, a lack of employee buy-in, the ambiguity and difficulty in defining defects, and the difficult decision-making process due to specific shortcomings in the Six Sigma methods. These shortcomings include an overreliance on trained Six Sigma experts, called black belts; a focus on corrective actions rather than a proactive approach, and a lack of interest in the importance of improving process velocity and the use of information technology.
Six Sigma is a process quality improvement methodology that utilizes “the concept of statistical thinking and encourages the application of well-proven statistical tools and techniques for defect reduction through process variability reduction methods,” according to Pros and Cons of Six Sigma, written by Jiju Antony. A successful Six Sigma implementation effort results in a process output defective rate of .00034 percent or less.
The initial investment and ongoing costs of implementing Six Sigma methods can actually do more harm than good and can scare many small businesses from incorporating Six Sigma into their business process. Retrieving and analyzing the necessary information to make the data-driven decisions required by Six Sigma can be costly and time consuming. This initial investment varies greatly among companies and processes depending on the size of the process and the amount of relevant data previously collected before the Six Sigma implementation. If no useful data has been collected on the process before deciding to implement Six Sigma, retrieving the necessary information can take weeks to months of paying outside consultants and/or losing productivity from current employees to refocus their efforts.
Any quality improvement method such as Six Sigma requires employee buy-in and needs to become part of the organizational culture. This is difficult to achieve with Six Sigma because of the overreliance on trained and certified experts of the Six Sigma methodologies; these so-called black belts, which many companies have to pay as outside consultants, create a division in the organization rather than a synergy, and do not always utilize all employees and their expertise in the improvement process. Employees who work within the process every day have a great deal of experience and expertise compared to outside consultants trained in Six Sigma techniques; many of these employees know the weaknesses and frustrations of the process firsthand and can provide recommendations for solutions, but they're often overlooked because they are not Six Sigma experts.
A defect is any process output that cannot be used; therefore, a defect is seen as a wasted resource because it would result in customer dissatisfaction. Defining a defect can be difficult for any business process that isn’t a standardized manufacturing process, especially innovative business processes. Proponents of Six Sigma believe the methods can be used in any business environment, including the service industry, but defects in industries such as these can be difficult to define and measure because Six Sigma defines defects with the assumption of normality and ignores the severity of defects. A defect in the service industry resulting in customer dissatisfaction can range from a simple misunderstanding of terminology to complete disrespect by the employee towards the customer; these two outcomes receive the same value in Six Sigma methods because they both cause customer dissatisfaction, but they completely differ in the overall result of the organization’s customer satisfaction levels.
The decision-making process is often left to a select few individuals, often combining outside consultants trained in Six Sigma and upper management. A problem with this decision-making process is the focus on a corrective approach instead of a proactive, preventative approach. A proactive approach is crucial because marketplace demands are constantly changing and an output not considered a defect today may be seen as a defect by the consumer in the near future. This corrective approach can result in management deciding to undergo a process redesign effort because the continuous improvement efforts failed to reach the Six Sigma threshold; an easier and less expensive fix to improve production and the bottom line could be to focus on improving the speed and efficiency of the process instead of just quality.