To understand the performance of a given process, however, the absolute total number of its measured defects shall be related to the total number of defects opportunities. Those defects do not refer uniquely to the final product, as they may occur at different levels and within each micro-process, by which the process is composed 8. A mean per se may be in line with the industry standards, while a process can still contain plenty of defects (deviation from the standard).

To understand a process performance with specific regard to its fallacy, the analysis of the mean is often useless. The variability shall thus be reduced as much as possible to eliminate the risk of defects in the final product or service and to make it a reliable, safe, and capable process. One of the fundamental assumptions of the whole theoretical complex of this methodology is the interpretation of the process variability as the main source of errors, inefficiency, and poor quality. the clear identification, within each micro-process by which the process is composed, of Suppliers, Inputs, Process, Outputs, and Customers 6, 7. This interpretation of the concept of pervasive customer satisfaction, functional to the achievement of the so-called ‘total quality’ within the organization, is central in the Six Sigma philosophy and is reflected by its methodology, based on the SIPOC identification, i.e. In the context of modern complexity, the ‘customer’ is any stakeholder in the process, from the next person who utilizes the intermediate output of a micro-process within the organization (internal customer), to the end-user of the finished product (external customer) 4, 5. It implies the systematic collection and statistical analysis of data to understand a given, potential process optimization margin and subsequent reorganization of that process to improve it, thus meeting customers’ expectations. It consists of the systematic application of problem-solving techniques, consequent structured implementation of improvements, and the use of process behavioral studies to maintain the achievements 3. Six Sigma is a methodology for process continuous improvement born in the 1980s at Motorola and subsequently successfully applied to different processes 1, in different contexts, and by many manufacturing companies 2. In our experience the application of the Lean Six Sigma methodology to the process of handling the surgical instruments from/to the OR was cost-effective, significantly decreased the costs of poor quality and increased internal stakeholder satisfaction. Regarding personnel satisfaction, 150 questionnaires were answered, and the overall score improved from 6.6 ± 2.2 pts to 7.0 ± 1.9 pts (p = 0.013). The observed improvement was estimated in approximately $19,729 of cost savings. Through this supply chain passed 314,552 instruments in 2022 and 22 OR processes were regularly assessed. The primary outcome was the analysis of Sigma improvement. We applied the Six Sigma lean methodology by conducting workshops and practical exercises and by improving the surgical instrument process chain, as well as checking stakeholders’ satisfaction. The project was based on the surgical instrument supply chain analysis. The project was conducted at the operating theatre of our tertiary regional hospital during the period from July 2021 to December 2022. This longitudinal observational study aimed to assess the impact of Six-Sigma methodology to optimize surgical instrument sterilization processes. Operating room (OR) management is a complex multidimensional activity combining clinical and managerial aspects.

Success stories lean six sigma