Critical Characteristics are those product requirements (dimensions, performance tests) or process parameters that can affect compliance with government regulations of safe vehicle/product function and which require specific supplier, assembly, shipping, or monitoring and inclusion on Control Plans. Critical characteristics are identified with the inverted delta symbol

A function or an area in a manufacturing process or procedure, the failure of which, or loss of control over, may have an adverse affect on the quality of the finished product and may result in a unacceptable health risk

A review conducted to verify that the detailed design of one or more configuration items satisfy specified requirements; to establish the compatibility among the configuration items and other items of equipment, facilities, software, and personnel; to assess risk areas for each configuration item; and, as applicable, to assess the results of producibility analyses, review preliminary hardware product specifications, evaluate preliminary test planning, and evaluate the adequacy of preliminary operation and support documents. See: preliminary design review, system design review

The degree of impact that a requirement, module, error, fault, failure, or other item has on the development or operation of a system. Syn: severity

Analysis which identifies all software requirements that have safety implications, and assigns a criticality level to each safety-critical requirement based upon the estimated risk

Control chart that shows the cumulative sum of deviations from a set value in successive samples. Each plotted point indicates the algebraic sum of the last point and all deviations since

A control chart on which the plotted value is the cumulative sum of deviations of successive samples from a target value. The ordinate of each plotted point represents the algebraic sum of the previous ordinate and the most recent deviations from the target

Any recipient of a product or service; anyone who is affected by what one produces. A customer can be external or outside the organization, or they can be internal to the organization

(American)Introduced in 1994 by University of Michigan and American Society for Quality CSI measures customer satisfaction at national level. CSI has been on a continual decline from 1994 through 1997 suggesting that quality improvements are not keeping pace with consumer expectations

A long-term relationship between a buyer and supplier characterized by teamwork and mutual confidence. The supplier is considered an extension of the buyer's organization. The partnership is based on several commitments. The buyer provides long-term contracts and uses fewer suppliers. The supplier implements quality assurance processes so that incoming inspection can be minimized. The supplier also helps the buyer reduce costs and improve product and process designs

An information gathering tool to use with any work activity. It breaks down a job into its component parts: Customer Requirements and Supplier Requirements

A technique for error detection in data communications used to assure a program or data file has been accurately transferred. The CRC is the result of a calculation on the set of transmitted bits by the transmitter which is appended to the data. At the receiver the calculation is repeated and the results compared to the encoded value. The calculations are chosen to optimize error detection. Contrast with check summation, parity check

(1) (McCabe) The number of independent paths through a program. (2) (NBS) The cyclomatic complexity of a program is equivalent to the number of decision statements plus 1

Factual information used as a basis for reasoning, discussion, or calculation; often refers to quantitative information

(1) Evaluation of the description and intended use of each data item in the software design to ensure the structure and intended use will not result in a hazard. Data structures are assessed for data dependencies that circumvent isolation, partitioning, data aliasing, and fault containment issues affecting safety, and the control or mitigation of hazards. (2) Evaluation of the data structure and usage in the code to ensure each is defined and used properly by the program. Usually performed in conjunction with logic analysis

Gathering facts on how a process works and/or how a process is working from a customer's point of view. All data collection is driven by a knowledge of the process and guided by statistical principles

(1) A collection of the names of all data items used in a software system, together with relevant properties of those items; e.g., length of data item, representation, etc. (2) A set of definitions of data flows, data elements, files, data bases, and processes referred to in a leveled data flow diagram set

A software V&V task to ensure that the input and output data and their formats are properly defined, and that the data flows are correct

A diagram that depicts data sources, data sinks, data storage, and processes performed on data as nodes, and logical flow of data as links between the nodes. Syn: data flowchart, data flow graph

A process used to determine if data are inaccurate, incomplete, or unreasonable. The process may include format checks, completeness checks, check key tests, reasonableness checks and limit checks. (2) The checking of data for correctness or compliance with applicable standards, rules, and conventions

A test coverage criteria requiring enough test cases such that each decision has a true and false result at least once, and that each statement is executed at least once. Syn: branch coverage. Contrast with condition coverage, multiple condition coverage, path coverage, statement coverage

A tool used to evaluate problems, solutions, or ideas. The possibilities are listed down the left-hand side of the matrix and relevant criteria are listed across the top. Each possibility is then rated on a numeric scale of importance or effectiveness (e.g. on a scale of 1 to 10) for each criterion, and each rating is recorded in the appropriate box. When all ratings are complete, the scores for each possibility are added to determine which has the highest overall rating and thus deserves the greatest attention

A product’s or service’s nonfulfillment of an intended requirement or reasonable expectation for use, including safety considerations. There are four classes of defects: Class 1, Very Serious, leads directly to severe injury or catastrophic economic loss; Class 2, Serious, leads directly to significant injury or significant economic loss; Class 3, Major, is related to major problems with respect to intended normal or reasonably foreseeable use; and Class 4, Minor, is related to minor problems with respect to intended normal or reasonably foreseeable use (see also “blemish”, “imperfection”,and “nonconformity”)

A personal performance standard that says specifications should be met every time. An attitude that displays personal commitment to doing the job right the first time, every time

A control chart for evaluating a process in terms of a demerit (or quality score), i.e., a weighted sum of counts of various classified nonconformities

Alternate name for the Plan-Do-Check-Act cycle, a four-stage approach to problem-solving. It is also sometimes called the Shewhart cycle

Award given annually to organizations that, according to the award guidelines, have successfully applied companywide quality control based on statistical quality control and will keep up with it in the future. Although the award is named in honor of W. Edwards Deming, its criteria are not specifically related to Deming's teachings. There are three separate divisions for the award: the Deming Application Prize, the Deming Prize for Individuals, and the Deming Prize for Overseas Companies. The award process is overseen by the Deming Prize Committee of the Union of Japanese Scientists and Engineers in Tokyo

A prominent consultant, teacher, and author on the subject of quality. After sharing his expertise in statistical quality control to help the U.S. war effort during World War II, the War Department sent Deming to Japan in 1946 to help that nation recover from its wartime losses. Deming published more than 200 works, including the well-known books Quality, Productivity, and Competitive Position and Out of the Crisis. Deming, who developed the 14 points for managing, is an ASQ Honorary member

The function which yields the probability that a particular random variable takes on any one of its possible values

The degree to which a product is operable and capable of performing its required function at any randomly chosen time during its specified operating time, provided that the product is available at the start of that period. (Nonoperation-related influences are not included.) Dependability can be expressed by the ratio: time available divided by (time available + time required)

A simultaneous engineering process designed to optimize the relationship between design function, manufacturability, and ease of assembly

A mistake proofing checklist designed to assure that all important items were considered in establishing design requirements

A branch of applied statistics dealing with planning, conducting, analyzing, and interpreting controlled tests to evaluate the factors that control the value of a parameter or group of parameters

The period of time in the software life cycle during which the designs for architecture, software components, interfaces, and data are created, documented, and verified to satisfy requirements

A specification that documents how a system is to be built. It typically includes system or component structure, algorithms, control logic, data structures, data set [file] use information, input/output formats, interface descriptions, etc Contrast with design standards, requirement. See: software design description