Maintainability The probability that a failed system can be made operable in a specified interval or downtime.

Maintainability. (IEEE) The ease with which a software system or component can be modified to correct faults, improve performance or other attributes, or adapt to a changed environment. Syn: modifiability

Maintenance. (QA) Activities such as adjusting, cleaning, modifying, overhauling equipment to assure performance in accordance with requirements. Maintenance to a software system includes correcting software errors, adapting software to a new environment, or making enhancements to software See: adaptive maintenance, corrective maintenance, preventive maintenance.

Management Systems Software tools for supporting the modeling, analysis, and enactment of business processes.

Master Black Belt A teacher and mentor of Black Belts. Provides support, reviews projects, and undertakes larger scale projects.

Matrix Analysis method quantifies and arranges matrix diagram data so that the information is easy to visualize and comprehend. The relationships between the elements shown in a matrix diagram are quantified by obtaining numerical data for intersection cells. Of the seven new QC tools, this is the only numerical analysis method. The results of this technique, however, are presented in diagram form. ... One major technique that this method also utilizes is known as principal components analysis.

Matrix Diagram method clarifies problematic spots through multidimensional thinking. ... The matrix diagram method identifies corresponding elements involved in a problem situation or event. These elements are arranged in rows and columns on a chart that shows the presence or absence of relationships among collected pairs of elements. ... Effective problem solving is facilitated at the intersection points, also referred to as the idea conception points. ... Matrix diagram are classified on the basis of their pattern into five groups: (1) the L type matrix, (2) the T type matrix, (3) the Y type matrix, (4) the X type matrix, and (5) the C type matrix.

MBNA Malcolm Baldrige National Quality Award: An annual award given to a United States company that excels in quality management and quality achievement. [Same as Baldrige Award.]

MBTI Myers Briggs Type Indicator

Measurement The assignment of numbers to actions or events.

Mean The average of a group of measurement values. Mean is determined by dividing the sum of the values by the number of values in the group.
mean time between failures. A measure of there liability of a computer system, equal to average operating time of equipment between failures, as calculated on a statistical basis from the known failure rates of various components of the system.

Mean time to failure (MTF). A measure of reliability, giving the average time before the first failure.

Mean time to repair (MTR). A measure of reliability of a piece of repairable equipment, giving the average time between repairs.
measurable. Capable of being measured.

Measure. (IEEE) A quantitative assessment of the degree to which a software product or process possesses a given attribute.
measurement. The process of determining the value of some quantity in terms of a standard unit.

Median The middle of a group of measurement values when arranged in numerical order. For example, in the group (32, 45, 78, 79, 101), 78 is the median. If the group contains an even number of values, the median is the average of the two middle values.

Metric, software quality. (IEEE) A quantitative measure of the degree to which software possesses a given attribute which affects its quality.

Mission statement A written declaration of the purpose of an organization or project team. Organizational mission or vision statements often include an organizational vision for the future, goals, and values. Mission describes the activities for achieving the Vision. The Mission is the cause and the Vision the effect. The Mission statement may also contain verb (design, train, maintain, etc.) + object (system, strategy, etc.) + target value (how much, #, %, etc. This is optional) + time limit (should be same time frame as Vision)

Mode The most frequently occurring value in a group of measurements

MSA Measurement System Analysis.

MTBF Mean Time Between Failure

MTTF. mean time to failure.

MTTR. mean time to repair.

Multiple condition coverage. (Myers) A test coverage criteria which requires enough test cases such that all possible combinations of conditions outcomes in each decision, and all points of entry, are invoked at least once. Contrast with branch coverage, condition, decision coverage, path coverage, path coverage, statement coverage.

Mutation analysis. (NBS) A method to determine test set thoroughness by measuring the extent to which a test set can discriminate the program from slight variants [mutants] of the program.

NCR Non Conformance Report

Noise In the context of quality management, noise is essentially variability. For example, if you are making ketchup, noise in the process comes from variations in the quality of incoming tomatoes, in changes in ambient temperature and humidity, in variations in machinery performance, in variations in the quality of human factors, etc.

Nominal Unordered categories which indicate membership or non membership with no implication of quantity, i.e., assembly area number one, part numbers, etc.

Nominal group technique Technique used to encourage creative thinking and new ideas, but is more controlled than brainstorming. Each member of a group writes down his or her ideas and then contributes one to the group pool. All contributed ideas are then discussed and prioritized.

Non Value Added Activity An activity performed in a process that does not add value to the output product or service, which may or may not have a valid business reason for being performed.

Non-Conformance Product or material which does not conform to the customer specifications and/or requirements. Sometimes used interchangeably with non-conformity.
Non-Conforming Product Product which does not conform to the customer specifications and/or requirements. Same as Non-Conformance.

Non-Conformity Nonfulfilment of a specified requirement. Sometimes used interchangeably with non-conformance.

Non-critical code analysis .(IEEE) (1) Examines software elements that are not designated safety-critical and ensures that these elements do not cause a hazard. (2) Examines portions of the code that are not considered safety-critical code to ensure they do not cause hazards. Generally, safety-critical code should be isolated from non-safety-critical code. This analysis is to show this isolation is complete and that interfaces between safety-critical code and non-safety-critical code do not create hazards.

NORMAL DISTRIBUTION A continuous, symmetrical density function characterized by a bell shaped curve, e.g., distribution of sampling averages.

np chart A control chart indicating the number of defective units in a given sample.

Null hypothesis is typically a hypothesis of no difference. That is why the word "null" in "null hypothesis" is used -- it is the hypothesis of no difference. Despite the "null" in "null hypothesis," there are occasions when the parameter is not hypothesized to be 0. For example the null hypothesis may be that the parameter is equal to a specific value.