This article needs additional citations for verification .(June 2009) |
Eight Disciplines Methodology (8D) is a method or model developed at Ford Motor Company used to approach and to resolve problems, typically employed by quality engineers or other professionals. Focused on product and process improvement, its purpose is to identify, correct, and eliminate recurring problems. [1] It establishes a permanent corrective action based on statistical analysis of the problem and on the origin of the problem by determining the root causes. Although it originally comprised eight stages, or 'disciplines', it was later augmented by an initial planning stage. 8D follows the logic of the PDCA cycle. The disciplines are:
8Ds has become a standard in the automotive, [2] assembly, and other industries that require a thorough structured problem-solving process using a team approach.
The executives of the Powertrain Organization (transmissions, chassis, engines) wanted a methodology where teams (design engineering, manufacturing engineering, and production) could work on recurring chronic problems. In 1986, the assignment was given to develop a manual and a subsequent course that would achieve a new approach to solving identified engineering design and manufacturing problems. The manual for this methodology was documented and defined in Team Oriented Problem Solving (TOPS), first published in 1987. The manual and subsequent course material were piloted at Ford World Headquarters in Dearborn, Michigan. Ford refers to their current variant as G8D (Global 8D). The Ford 8Ds manual is extensive and covers chapter by chapter how to go about addressing, quantifying, and resolving engineering issues. It begins with a cross-functional team and concludes with a successful demonstrated resolution of the problem. Containment actions may or may not be needed based on where the problem occurred in the life cycle of the product.
Many disciplines are typically involved in the "8Ds" methodology. The tools used can be found in textbooks and reference materials used by quality assurance professionals. For example, an "Is/Is Not" worksheet is a common tool employed at D2, and Ishikawa, or "fishbone," diagrams and "5-why analysis" are common tools employed at step D4. In the late 1990s, Ford developed a revised version of the 8D process that they call "Global 8D" (G8D), which is the current global standard for Ford and many other companies in the automotive supply chain. The major revisions to the process are as follows:
Recently, the 8D process has been employed significantly outside the auto industry. As part of lean initiatives and continuous-improvement processes it is employed extensively in the food manufacturing, health care, and high-tech manufacturing industries.
The benefits of the 8D methodology include effective approaches to finding a root cause, developing proper actions to eliminate root causes, and implementing the permanent corrective action. The 8D methodology also helps to explore the control systems that allowed the problem to escape. The Escape Point is studied for the purpose of improving the ability of the Control System to detect the failure or cause when and if it should occur again. Finally the Prevention Loop explores the systems that permitted the condition that allowed the Failure and Cause Mechanism to exist in the first place.
Requires training in the 8D problem-solving process as well as appropriate data collection and analysis tools such as Pareto charts, fishbone diagrams, and process maps.
The following tools can be used within 8D:
The 8D methodology was first described in a Ford manual in 1987. The manual describes the eight-step methodology to address chronic product and process problems. The 8Ds included several concepts of effective problem solving, including taking corrective actions and containing nonconforming items. These two steps have been very common in most manufacturing facilities, including government and military installations. In 1974, the U.S. Department of Defense (DOD) released “MIL-STD 1520 Corrective Action and Disposition System for Nonconforming Material”. This 13 page standard defines establishing some corrective actions and then taking containment actions on nonconforming material or items. It is focused on inspection for defects and disposing of them. The basic idea of corrective actions and containment of defectives was officially abolished in 1995, but these concepts were also common to Ford Motor Company, a major supplier to the government in World War II. Corrective actions and containment of poor quality parts were part of the manual and course for the automotive industry and are well known to many companies. Ford's 60 page manual covers details associated with each step in their 8D problem solving manual and the actions to take to deal with identified problems.
The exact history of the 8D method remains disputed as many publications and websites state that it originates from the US military. Indeed, MIL-STD-1520C [3] outlines a set of requirements for their contractors on how they should organize themselves with respect to non-conforming materials. Developed in 1974 and cancelled in February 1995 as part of the Perry memo, [4] you can compare it best to the ISO 9001 standard that currently exists as it expresses the same philosophy. The aforementioned military standard does outline some aspects that are in the 8D method, however, it does not provide the same structure that the 8D methodology offers. Taking into account the fact that the Ford Motor Company played an instrumental role in producing army vehicles during the Second World War and in the decades after, it could very well be the case that the MIL-STD-1520C stood as a model for today's 8D method. [5]
FMEA (failure mode and effect analysis) is a tool generally used in the planning of product or process design. The relationships between 8D and FMEA are outlined below:
The FMEA and 8D should reconcile each failure and cause by cross documenting failure modes, problem statements and possible causes. Each FMEA can be used as a database of possible causes of failure as an 8D is developed.
Safety engineering is an engineering discipline which assures that engineered systems provide acceptable levels of safety. It is strongly related to industrial engineering/systems engineering, and the subset system safety engineering. Safety engineering assures that a life-critical system behaves as needed, even when components fail.
Ishikawa diagrams are causal diagrams created by Kaoru Ishikawa that show the potential causes of a specific event.
Hazard analysis and critical control points, or HACCP, is a systematic preventive approach to food safety from biological, chemical, and physical hazards in production processes that can cause the finished product to be unsafe and designs measures to reduce these risks to a safe level. In this manner, HACCP attempts to avoid hazards rather than attempting to inspect finished products for the effects of those hazards. The HACCP system can be used at all stages of a food chain, from food production and preparation processes including packaging, distribution, etc. The Food and Drug Administration (FDA) and the United States Department of Agriculture (USDA) require mandatory HACCP programs for juice and meat as an effective approach to food safety and protecting public health. Meat HACCP systems are regulated by the USDA, while seafood and juice are regulated by the FDA. All other food companies in the United States that are required to register with the FDA under the Public Health Security and Bioterrorism Preparedness and Response Act of 2002, as well as firms outside the US that export food to the US, are transitioning to mandatory hazard analysis and risk-based preventive controls (HARPC) plans.
In science and engineering, root cause analysis (RCA) is a method of problem solving used for identifying the root causes of faults or problems. It is widely used in IT operations, manufacturing, telecommunications, industrial process control, accident analysis, medicine, healthcare industry, etc. Root cause analysis is a form of inductive and deductive inference.
A remedial action is a change made to a nonconforming product or service to address the deficiency. This also can refer to restoration of a landscape from industrial activity
Failure mode and effects analysis is the process of reviewing as many components, assemblies, and subsystems as possible to identify potential failure modes in a system and their causes and effects. For each component, the failure modes and their resulting effects on the rest of the system are recorded in a specific FMEA worksheet. There are numerous variations of such worksheets. An FMEA can be a qualitative analysis, but may be put on a quantitative basis when mathematical failure rate models are combined with a statistical failure mode ratio database. It was one of the first highly structured, systematic techniques for failure analysis. It was developed by reliability engineers in the late 1950s to study problems that might arise from malfunctions of military systems. An FMEA is often the first step of a system reliability study.
Troubleshooting is a form of problem solving, often applied to repair failed products or processes on a machine or a system. It is a logical, systematic search for the source of a problem in order to solve it, and make the product or process operational again. Troubleshooting is needed to identify the symptoms. Determining the most likely cause is a process of elimination—eliminating potential causes of a problem. Finally, troubleshooting requires confirmation that the solution restores the product or process to its working state.
Reliability engineering is a sub-discipline of systems engineering that emphasizes the ability of equipment to function without failure. Reliability describes the ability of a system or component to function under stated conditions for a specified period of time. Reliability is closely related to availability, which is typically described as the ability of a component or system to function at a specified moment or interval of time.
Advanced product quality planning (APQP) is a framework of procedures and techniques used to develop products in industry, particularly in the automotive industry. It differs from Six Sigma in that the goal of Six Sigma is to reduce variation, but has similarities to Design for Six Sigma (DFSS).
A measurement system analysis (MSA) is a thorough assessment of a measurement process, and typically includes a specially designed experiment that seeks to identify the components of variation in that measurement process. Just as processes that produce a product may vary, the process of obtaining measurements and data may also have variation and produce incorrect results. A measurement systems analysis evaluates the test method, measuring instruments, and the entire process of obtaining measurements to ensure the integrity of data used for analysis and to understand the implications of measurement error for decisions made about a product or process. Proper measurement system analysis is critical for producing a consistent product in manufacturing and when left uncontrolled can result in a drift of key parameters and unusable final products. MSA is also an important element of Six Sigma methodology and of other quality management systems. MSA analyzes the collection of equipment, operations, procedures, software and personnel that affects the assignment of a number to a measurement characteristic.
DMAIC or define, measure, analyze, improve and control refers to a data-driven improvement cycle used for optimizing and stabilizing business processes and designs. The DMAIC improvement cycle is the core tool used to drive Six Sigma projects. However, DMAIC is not exclusive to Six Sigma and can be used as the framework for other improvement applications.
Failure mode effects and criticality analysis (FMECA) is an extension of failure mode and effects analysis (FMEA).
Five whys is an iterative interrogative technique used to explore the cause-and-effect relationships underlying a particular problem. The primary goal of the technique is to determine the root cause of a defect or problem by repeating the question "Why?" five times. The answer to the fifth why should reveal the root cause of the problem.
A failure reporting, analysis, and corrective action system (FRACAS) is a system, sometimes carried out using software, that provides a process for reporting, classifying, analyzing failures, and planning corrective actions in response to those failures. It is typically used in an industrial environment to collect data, record and analyze system failures. A FRACAS system may attempt to manage multiple failure reports and produces a history of failure and corrective actions. FRACAS records the problems related to a product or process and their associated root causes and failure analyses to assist in identifying and implementing corrective actions.
The seven management and planning tools have their roots in operations research work done after World War II and the Japanese total quality control (TQC) research.
Accident analysis is a process carried out in order to determine the cause or causes of an accident so as to prevent further accidents of a similar kind. It is part of accident investigation or incident investigation. These analyses may be performed by a range of experts, including forensic scientists, forensic engineers or health and safety advisers. Accident investigators, particularly those in the aircraft industry, are colloquially known as "tin-kickers". Health and safety and patient safety professionals prefer using the term "incident" in place of the term "accident". Its retrospective nature means that accident analysis is primarily an exercise of directed explanation; conducted using the theories or methods the analyst has to hand, which directs the way in which the events, aspects, or features of accident phenomena are highlighted and explained. These analyses are also invaluable in determining ways to prevent future incidents from occurring. They provide good insight by determining root causes, into what failures occurred that lead to the incident.
Corrective and preventive action consists of improvements to an organization's processes taken to eliminate causes of non-conformities or other undesirable situations. It is usually a set of actions, laws or regulations required by an organization to take in manufacturing, documentation, procedures, or systems to rectify and eliminate recurring non-conformance. Non-conformance is identified after systematic evaluation and analysis of the root cause of the non-conformance. Non-conformance may be a market complaint or customer complaint or failure of machinery or a quality management system, or misinterpretation of written instructions to carry out work. The corrective and preventive action is designed by a team that includes quality assurance personnel and personnel involved in the actual observation point of non-conformance. It must be systematically implemented and observed for its ability to eliminate further recurrence of such non-conformation. The Eight disciplines problem solving method, or 8D framework, can be used as an effective method of structuring a CAPA.
Process Decision Program Chart (PDPC) is a technique designed to help prepare contingency plans. The emphasis of the PDPC is to identify the consequential impact of failure on activity plans, and create appropriate contingency plans to limit risks. Process diagrams and planning tree diagrams are extended by a couple of levels when the PDPC is applied to the bottom level tasks on those diagrams.
SDI Tools is a set of commercial software add-in tools for Microsoft Excel developed and distributed by Statistical Design Institute, LLC., a privately owned company located in Texas, United States.
A3 problem solving is a structured problem-solving and continuous-improvement approach, first employed at Toyota and typically used by lean manufacturing practitioners. It provides a simple and strict procedure that guides problem solving by workers. The approach typically uses a single sheet of ISO A3-size paper, which is the source of its name. More contemporary versions include the Systems-oriented A3