Six Sigma Terminology - D to F

Defining terminology and solving doubts on them is a vital part you do as a six sigma expert. Terminologies are descriptive in nature and should be understood before moving ahead in studies.

Data

Data are factual information used as a basis for reasoning, discussion, or calculation; often this term refers to quantitative information. It is plural in form. The singular is “datum.”

Defect

Any undesired result is a defect.

A failure to meet one of the acceptance criteria of your customers. A defective unit may have one or more defects. ‘A defect is an inability to conform to requirements’ (Crosby, ‘Quality Is Free’), whether or not those requirements have been articulated or specified.

Defective

The word defective describes an entire unit that fails to meet acceptance criteria, regardless of the number of defects within the unit. A unit may be defective because of one or more defects.

Defects (%)

Once you have determined the operational definition of what constitutes a defect:

The total number of defects counted on the population in question divided by the total population count.

Defects Per Million Opportunities - DPMO

Defects per million opportunities (DPMO) is the average number of defects per unit observed during an average production run divided by the number of opportunities to make a defect on the product under study during that run normalized to one million.

Defects Per Unit - DPU

DPU or Defects Per Unit is the average number of defects observed when sampling a population. 

DPU = Total # of Defects / Total population

Definition of Quality

Anticipate and honor the need of an intending user.

Dependent Variable

A variable that can change the desired output.

Design for Six Sigma - DFSS

DFSS is the acronym for Design for Six Sigma. Methodologies that have been widely used for DFSS include DMADV and IDOV.

DFMEA

DFMEA (Design Failure Mode and Effect Analysis) is the application of the Failure Mode and Effects Analysis (FMEA) method specifically to product/service design.

Effect

An effect is that which is produced by a cause; the impact a factor (X) has on a response variable (Y).

Efficacy

The power or ability to cause the desired effect

Efficiency

A measure of productivity, with the goal being to maximum productivity with minimum wasted effort or expense.

A term denoting to the relationship between outputs and inputs. It requires generating higher outputs as related to inputs. It means enhancing productivity, i.e., less rework, fewer errors and optimal use of resources.

Empowerment

A series of actions designed to give employees greater control over their working lives. Businesses give employees empowerment to motivate them according to the theories of Abraham Maslow and Fredrick Herzberg.

To invest with power or give authority to complete. To empower employees.Being allowed to make decisions and take actions on your own, apart from management.

Entitlement

As good as a process can get without capital investment.A perceived “right to demand.” Opposite of a gift, in that it is without appreciation. A “you owe me” obligation for which, I owe nothing in return.

Error

Error, also called residual error, refers to variation in observations made under identical test conditions, or the amount of variation that can not be attributed to the variables included in the experiment.

Error (Type I)

The error that concludes that someone is guilty when in fact, they are not. (Ho true, but I rejected it–concluded Ha). Also known as ALPHA error. Also known as Producer’s risk.

Error (Type II)

The error that concludes that someone is not guilty when in fact, they are. (Ha true, but I concluded Ho). BETA

Accept a hypothesis or statement as true when it is false: Ho is false, but I conclude Ho is true. The error that concludes that someone is not guilty when in fact, he or she is. (accept Ho as true, being false, when Ha is true).

F test

F test – test of whether two samples are drawn from different populations have the same standard deviation, with specified confidence level. Samples may be of different sizes.

F-Chart

An F-Chart is a chart that carries a significant amount of misleading information, rendering it unfit for the intended analysis.

Factor

A factor is an independent variable; an X.

FISH

Inventory Control – instead of FIFO or LIFO – some organizations use FISH – first in still here!

Fishbone

A tool used to solve quality problems by brainstorming causes and logically organizing them by branches. Also called the Cause & Effect diagram and Ishikawa diagram.

Form / Format

The form is a pre-defined template required to be used in a Process/instruction for information/data collection.

Failure Mode and Effects Analysis (FMEA)

A procedure and tools that help to identify every possible failure mode of a process/product and to determine the effect of the failure modes on other sub-items and the required function of the product or process. The FMEA is also used to rank and prioritize the possible causes of failures as well as develop and implement preventative actions, with responsible persons assigned to carry out these actions.