Design structure matrix: Difference between revisions

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===DSM marking===

Initially, the off-diagonal cell markings indicated only the existence/non-existence of an interaction (link) between elements, using a symbol (or the figure '1'). Such marking is defined as '''Binary DSM'''. The marking then has developed to indicate quantitative relation '''Numeric DSM''' indicating the "strength" of the linkage, or statistical relations '''Probability DSM''' indicating for example the probability of applying new information (that require reactivation of the linked activity).<ref name{{CN|date="complex"/>October 2021}}

==DSM algorithms==

The DSM algorithms are used for reordering the matrix elements subject to some criteria. Static DSMs are usually analyzed with [[Cluster analysis|clustering algorithms]] (i.e., reordering the matrix elements in order to group together related elements). Clustering results would typically show groups (clusters) of tightly related elements, and elements that are either not connected or are connected to many other elements and therefore are not part of a group.<ref name="DSMbook"/>

Time-based DSMs are typically analyzed using partitioning, tearing and sequencing algorithms.<ref name="DSMbook"/><ref name="complex"/><ref>A. Karniel and Y. Reich, [https://link.springer.com/chapter/10.1007%2F978-0-85729-570-5_3 "Design process planning using DSM"], in Managing the Dynamics of New Product Development Processes: A New Product Lifecycle Management Paradigm, Springer, 2011 </ref>

'''Sequencing''' methods try to order the matrix elements such that no feedback marks remain.<ref name="DSMbook"/><ref name="complex"/> In case of coupled activities (activities that have cyclic links, e.g., activity A is linked to B, which is linked to C, which is linked to A) the results is a block diagonal DSM (i.e., blocks or groups of coupled activities along the diagonal). Partitioning methods include: [[path searching]]; [[reachability matrix]]; [[triangulation]] algorithm; and the powers of the Adjacency Matrix.

'''Tearing''' is the removal of feedback marks (in Binary DSM) or assignment of lower priority (numeric DSM). Tearing of a Component-based DSM may imply modularization (the component design is not influencing other components) or standardization (the component design is not influencing and not influenced by other components).<ref name="DSMbook"/><ref name="complex"/><ref>Sered Y, Reich Y (2006)," Standardization and modularization driven by minimizing overall process effort." Computer-Aided Design, 38(5):405-416</ref> After tearing a partitioning algorithm is reapplied.

Minimizing feedback loops gets the best results for Binary DSM, but not always for Numeric DSM or Probability DSM. '''Sequencing''' algorithms (using [[optimization]], [[genetic algorithms]]) are typically trying to minimize the number of [[feedback loop]]s and also to reorder coupled activities (having cyclic loop) trying to have the feedback marks close to the diagonal. Yet, sometimes the algorithm just tries to minimize a criterion (where minimum iterations is not the optimal results).<ref name="DSMsim">T. Browning: [https://dx.doi.org/10.1109/TEM.2002.806709 "Modeling Impacts of Process Architecture on Cost and Schedule Risk in Product Development"], In: ''IEEE Transactions on Engineering Management.'' 49(4):428-442, 2002.</ref>