Six Sigma Fundamentals: A Complete Introduction to the System, Methods, and Tools

Perhaps as a subsystem to service, one may include the issue of safety as part of the concerns and anticipated expectations of a program that is supposed to deliver perfection. Much time and effort is being spent on safety from both the organization's and government's perspective. In fact, OSHA's (Occupational Safety and Health Administration's) responsibility and function are precisely to overview and provide approaches to safety. One such compliance methodology is program safety management (PSM). Of course, compliance is a requirement of PSM, but it is not the only one. In addition, PSM is interested in establishing programs that demonstrate return, not only through enhanced safety culture and performance, but through the improvement of process reliability and operability.

Therefore, an important objective of PSM is the minimization of unwanted deviations from normal process operations. Improved process reliability, measured for example, as decreased process downtime, should be a collateral benefit of the program. The objective of achieving this benefit can be explicitly incorporated into the program through process hazard analyses procedure, and the way in which risk and reliability criteria form the basis for the mechanical integrity program.

In developing PSM programs we:

• Show what has and has not worked for peers by reviewing precedents set by OSHA in the interpretation and enforcement of the PSM standard.

• Establish a dynamic, flexible program addressing activities, record keeping and accountabilities, that can be systematically and conveniently revised as improvements in practice are identified.

• Fully integrate the program with other safety and reliability programs in place at the site, such as an EPA risk management program (RMP), or other related OSHA, EPA, corporate or industry standard-based programs.

• Support specific technical needs under the program, related to areas such as emergency response planning, mechanical integrity program, development, written operating procedures, process hazard analyses, compliance audits, training, evaluation of safety instrumented systems and facility siting assessment.

By comparison, the fundamental objective of the six sigma methodology is to implement a measurement system that will facilitate strategy of continual process improvements, with tremendous sensitivity to deviations from standardized values. In this section, therefore we want to take the opportunity and do a cursory comparison between the six sigma methodology and the OSHA PSM standard, to identify similarities between the two approaches, and to demonstrate that the OSHA PSM standard is consistent with the fundamentals of six sigma.

As we already have discussed, the six sigma methodology derives its goals by addressing customer satisfaction and not product quality, as derived by other traditional quality systems. Therefore, measuring quality on an absolute scale, rather than referring to one standard or another, is one of the great innovations in the development of six sigma. Six sigma also provides tools for measurement and control of processes. In addition, six sigma is as much about changing attitudes as it is about introducing a systematic analytical approach to performance measurements. A zero defects quality attitude is very demanding and it is not compromising in issues such as long-term management commitment, involvement of all employees, intensive training, outsource usage, high levels of communication and massive allocations of internal resources.

In the six sigma methodology, the evaluation is conducted by using the DMAIC and the DCOV models (as before). The difference is that now we may want to focus even more on customer satisfaction and effectiveness.

Six sigma and the PSM program

Just like a six sigma program, pursuing a PSM program is a very complicated mission, and should be carried out with great care. Furthermore, PSM program implementation is a much tougher mission to accomplish, and it can be done in several ways. The OSHA PSM regulation specifies 14 elements to be taken into consideration when writing, implementing and maintaining PSM program. They are:

1. Employee participation.

2. Process safety information.

3. Process hazard analysis.

4. Operating procedure.

5. Training.

6. Contractors.

7. Pre-startup safety review.

8. Mechanical integrity.

9. Hot work permit.

10. Management of change.

11. Incident investigation.

12. Emergency planning and response.

13. Compliance audits.

14. Trade secrets.

PSM is much more difficult to implement than six sigma. However, a comparison of the six sigma methodology with the OSHA PSM regulations reveals a high level of similarity. Identifying six sigma elements in the OSHA PSM regulation requires substitution of the PSM program in a SIPOC (supplier of input to a process that adds values and delivers output to customer) map. This can be broken down as follows: The supplier inputs are operating the plant OSHA regulations. The process from start to stop is writing, implementing and maintaining the PSM program. The customer outcomes are no near-misses, no incidences, which is equivalent to six sigma's "zero defects."

A simple comparison of the PSM implementation with the DMAIC and DCOV models is shown in Table 8.1.

The critical OSHA PSM Elements

To better make the comparison between the elements of PSM and those of the six sigma methodology, one must clearly understand the critical PSM elements:

• Employee participation. Section 304 of the Clean Air Act Amendment (CAAA) states that employees and their representatives should take part in the decision making regarding the efforts that the employer should make in order to create a safe workplace. It is also required that the employer train and educate his employees and inform them of the findings of any incident investigation. Furthermore, the employer is required to consult with the employees' representatives regarding the conducting and development of hazard assessments and the development of accident prevention plans. This is parallel to six sigma, which recommends initiating personnel meetings to promote the acceptance of the program among the employees, to reduce resistance to change (Tennant 2001).

• Process safety information. OSHA requires compiling of process safety information before conducting a process hazards analysis. The process safety information is classified into three categories:

  • Information on the dangers of any highly hazardous chemical used or produced by the processes.

  • Information on the technology of the process.

  • Information on the equipment utilized in the process.

• Process hazard analysis. Process hazard analysis (PHA) is the most thorough element among the OSHA PSM elements. PHA is a sequence that systematically examines equipment, procedures and systems, handling regulated substance to identify hazards and to define solutions and corrective actions. The owner should initiate PHA and is required to determine priorities for conducting PHA according to the complexity of the process, its age and its history, and to document them. The rule determines the need for using methodologies in the analysis, and lists minimal methods, as what-if, checklist, what if/check list, HAZOP (hazard and operability study) as an examination procedure. Process hazard analysis' purpose is to identify all possible deviations from the way in which a design is expected to work and to identify all the hazards associated with these deviations. Where deviations arise that result in hazards, actions are generated that require design engineers to review and suggest solutions to either remove the hazard or reduce its risk to an acceptable level. These solutions are reviewed and accepted by the HAZOP team before implementation, by using FMEA (failure mode and effect analysis) and FTA (fault tree analysis) or other equivalent methods. The PHA shall address the following:

  • The hazards of the process.

  • The identification of any previous incident that had a likely potential for significant offsite consequences.

  • Engineering and administrative controls applicable to the hazards and their interrelationship and appropriate application of detection methodologies to provide early warning of releases. (Acceptable detection methods might include process monitoring and control instruments with alarms and detection hardware such as hydrocarbon sensors.)

  • Consequences of failure of engineering and administrative controls.

  • Stationary source siting.

  • Human factors.

  • A qualitative evaluation of a range of possible safety and health effects of failure of controls on public health and the environment.

  A PHA conducting team is required to consist of:

  • Members with expertise in engineering and process operation.

  • A member with specific knowledge in the process to be evaluated.

  • A member familiar with the specific PHA methodology.

    The management is required to verify that the findings will be addressed, and that the solution implementation will be scheduled. An update stage of the PHA is required every five years, at least. A typical update review will include:

    • The PHA element covers the measurement stage, the analysis stage and the improvement stage in the six sigma methodology. The PHA sequence is parallel to the following sub-processes of the DMAIC.

    • The measurements and the root cause analysis in the six sigma methodology are the results from the first part of the PHA (for instance, the FTA results of the current processes).

    • The clarification of the project scope (in the six sigma's analyzing stage) is the determination of the ways to solve the findings, to generate solution, to select the ideal solution and to implement the solution. These subelements are also subelements in the OSHA PSM.

    • Process standardization and remeasure that are taking place in the control stage of the six sigma methodology are equivalent to the documentation and the requirement for the periodic update of the PHA element of OSHA PSM regulation.

• Operating procedures. This element requires documentation of the proper and safe way of operating processes and equipment, and the proper way of handling chemicals that are regulated. The documentation should have detailed instructions as to the different operating stages (normal operation, start-ups, temporary and emergency operation and shutdowns), operating limits, safety and health considerations, and safety systems and their functions. The procedures are required to be reviewed when necessary, so that they will always reflect the current status. The operating procedure is an act of standardization and is equivalent to the control stage in the six sigma methodology.

• Training. An effective training program will significantly reduce the number of incidences and their severity. OSHA PSM regulations address training in order to practice the operating procedures. The regulations distinguishes between different cases of training:

  • Initial training.

  • Process overview to new assigned employees with special emphasis on scenarios that impact safety.

  • Refresher training.

    The importance of training is easily understood. A contribution of six sigma to the training element can be achieved by developing systems to measure training performance and effectiveness. The human resource department, with the help of a consulting firm and the master black belt, can take ownership of that process. (Training documentation, evaluation of training program effectiveness and schedules for reviewing and revising the program are also required.)

• Contractors. The employer must obtain and evaluate information regarding the contract employer safety performance programs and must inform the contract employer regarding the variety of hazards that characterize the area of work. Furthermore, the employer must ensure that the contract employer and its employees will be provided with appropriate information and training and will be familiar with the plant emergency response plan. (The contractor element is not applicable to six sigma implementation).

• Mechanical integrity. The mechanical integrity element fills a missing part in the PHA element. The maintenance program ensures that the equipment will perform according to the appropriate reliability information. The program must include documentation regarding the preventive maintenance routine, capability, inspections and tests needed to verify its in operation condition. Any six sigma aspect that is valid to PHA is valid to mechanical integrity.

• Pre-startup review. The pre-startup review's purpose is to verify that new equipment installed, or modifications made, are ready to operate properly and safely. The review should verify the following:

  • Construction and equipment are in accordance with design specifications.

  • Safety, operating, maintenance and emergency procedures are in place and are adequate.

  • PHA has been performed to new stationary sources, and that resolutions have been implemented.

  • Modifications meet the management of change requirements.

  • Training has been completed, including training for new emergency response procedures.

• Management of change. A management of change (MOC) program is an administrative procedure that verifies that all aspects of changes and modifications have been considered, and that the appropriate managerial level has authorized the change. (A pre-startup review and management of change are processes that can always be improved and do not have direct relevancy to six sigma).

• Compliance audits. Re-measurement, impact evaluation and process standardization take place in the six sigma control stage. An audit process is a periodic examination of the process safety management program. Audit is a control stage that ensures compliance with OSHA PSM regulations by an overall program evaluation and is similar to the control stage in the six sigma methodology. The difference is on emphasis—the six sigma methodology is more interested in the effectiveness of the system, rather than compliance.

• Accident investigation. An accident investigation is a self-corrective element that addresses the prevention of the accident reoccurring. The investigation is required to begin within less than 48 hours following the accident and should be conducted by a team that is composed of persons with certain relevancy to the event, and at least one person knowledgeable with the process. Usually, documentation is required. The accident investigation is related to the six sigma improve stage.

• Emergency planning and response. The purpose of an emergency response program is to prepare to respond to, and the mitigation of, accidental releases and their impact on the public health and environment. The process's owner is required to establish and implement an emergency response plan for responding to, and for the mitigation of, the accidental release of regulated substances. (Note that all employees must be trained for emergency response and practice drills of the emergency response to evaluate the effectiveness.) The program is required to include the following:

  • Evacuation routes or protective actions for employees who are not directly involved in the process.

  • Procedure for employees responding to the release, including protective equipment use.

  • Technologies available for responding.

  • Procedures to inform the public and emergency response agencies about releases.

  • Procedures to inspect, test and maintain the emergency response equipment.

  • Documentation of first aid and emergency medical treatment for each of the substances that are under regulation.

    It is required that the emergency response will be coordinated with the local emergency response plans. Emergency response planning is different from other elements in the OSHA PSM regulations in terms of six sigma implementation. Two parameters influencing the plan's effectiveness are time and accuracy of response. Since both parameters are simply measurable, and since there are a variety of measures to improve the process of emergency response, it is applicable to the six sigma methodology.

• Hot permit work. Issuing a hot permit work is required for all hot work operations performed near covered processes. The permit lists all work's safety impacts and specifies the steps necessary to perform the work safely. Hot permit work is an element that can be improved by the six sigma methodology. Cutting and welding operations (commonly referred to as "hot work") are associated with machine shops, maintenance, and construction activities, as well as certain laboratory-related activities, such as glass blowing and torch soldering. Potential health, safety, and property hazards result from the fumes, gases, sparks, hot metal and radiant energy produced during hot work. Hot work equipment, which may produce high voltages or utilize compressed gases, also requires special awareness and training on the part of the worker to be used safely. The hazards associated with hot work can be reduced through the implementation of effective control programs. On the other hand, hot work permits should be developed by departments where cutting or welding is performed. Hot work permits can help minimize the risk of fire during cutting and welding activities by serving as a checklist for operators and those performing fire watch duties. The person responsible for issuing permits should be qualified to examine the work site and ensure that appropriate protective steps, such as those listed in this section, have been taken. A hot work permit should be issued at the beginning of each shift for each specific operation.

• Trade secrets. A trade secret indirectly contributes to six sigma, by forcing the organization to look at benchmarking and to be vigilant about the best in class.

PSM sigma metric

Process safety performance measurements are a hot topic in the safety industry. The purpose of the development of process safety performance measurements is to measure the contribution of a proactive approach and the efforts invested in that approach to the prevention of incidences. A process safety performance metric is an important issue. Six sigma is inherent in the PSM standard, but the missing part of six sigma is the sigma metric. Six sigma needs to calculate the quality of an absolute scale. In order to calculate the six sigma metric of an entity, the defects and the opportunity for defects must be defined.

Defect definition and data collections are easy. Each accident and each near miss are defects. The definition of the opportunities is more complicated. An opportunity can be a very simple operation of the process, like opening a cooling water valve to the reactor's jacket or inserting an agitator into work (opening a drinking water valve is not an opportunity). In addition, any maintenance working order will consist of at least one opportunity. The same is true for raw materials handling. By screening the entire operating procedure and other procedures, it is possible to count the opportunities created every day and to use an annual average for the six sigma calculation. Although it is possible that the computer will make an online counting of the opportunities, accidents and near misses should be counted manually, since there are only a few of them. Therefore, the sigma metric can be obtained by converting the DPMO, according to the table in Appendix B.

A calculation of the current sigma metric will probably reveal a surprising sigma metric value, that will be higher than this value in the production line.