INCOSE Systems Engineering Handbook, 5th Edition

APPENDIX D: N² DIAGRAM OF SYSTEMS ENGINEERING PROCESSES

Note: Figure D.1 in this appendix provides an N² diagram (see Section 3.2.4) of the typical inputs and outputs that appear in the IPO diagrams in this handbook. The off-diagonal squares represent the typical inputs/outputs shared by the processes that intersect at a given square. Outputs flow horizontally, inputs flow vertically, and the diagram can be read in a clockwise fashion. These typical inputs and outputs represent “a” way that the SE processes can be performed, but not necessarily “the” way that they must be performed. The absence of a relationship between any two processes does not preclude tailoring to create a relationship. Definitions of the typical inputs and outputs on the IPO diagrams can be found in Appendix E.

FIGURE D.1 Input/output relationships between the various SE processes. INCOSE SEH original figure created by Shortell, Walden, and Yip. Usage per the INCOSE Notices pages. All other rights reserved.

The system life cycle processes are placed on the diagonal, abbreviated as follows:

Abbreviation	Life Cycle Process	Handbook Section
ACQ	Acquisition	2.3.2.1
SUP	Supply	2.3.2.2
LCMM	Life Cycle Model Management	2.3.3.1
INFRAM	Infrastructure Management	2.3.3.2
PM	Portfolio Management	2.3.3.3
HRM	Human Resource Management	2.3.3.4
QM	Quality Management	2.3.3.5
KM	Knowledge Management