Page 398 - Design for Six Sigma for Service (Six SIGMA Operational Methods)

358 Chapter Ten

10.4.2 IDEF0 Process Mapping

IDEF0 (International DEFinition) process mapping is a method designed to
model the decisions, actions, and activities of an organization or system. It was
developed by the U.S. Department of Defense, mainly for the use of the U.S. Air
Force during the 1970s. Although it was developed over 30 years ago, the
Computer Systems Laboratory of the National Institute of Standards and
Technology (NIST) released IDEF0 as a standard for function modeling in FIPS
(Federal Information Processing Standards) Publication 183, December 1993.
Computer packages (for example, AI0 WIN) have been developed to aid
software development by automatically translating relational diagrams into code.

An IDEF0 diagram consists of boxes and arrows. It shows the function as a box
and the interfaces to or from the function as arrows entering or leaving the box.
Functions are expressed by boxes operating simultaneously with other boxes,
with the interface arrows constraining when and how operations are triggered
and controlled. The basic syntax for an IDEF0 model is shown in Fig. 10.8.

Mapping using this standard generally involves multiple levels. The first
level, the high-level map, identifies the major processes by which the
company operates (Peppard and Rowland 1995). The second-level map
breaks each of these processes into increasingly fine sub-processes until the
appropriate level of detail is reached.

For example, Fig. 10.9 shows the first-level IDEF0 process map of a printed-
circuit board (PCB) manufacturing process. Figure 10.10 shows the second-
level IDEF0 process map of the PCB manufacturing process, and you can
go further down with every subprocess.

There are a number of strengths and weaknesses associated with IDEF0.
The main strength is that it is a hierarchical approach, so users can choose
the mapping at their desired level of detail.

Controls

Inputs Process Outputs

Mechanisms
Figure 10.8 A Basic IDEF0 Process Map Template