Fisher et al. (1988a) propose to use this hierarchy when performing controllability analysis,
and Ponton and Laing (1993) point out that this hierarchy, (e.g. level 2 to level 5) could
also be used for control system design. This framework enables parallel development for the
process and the control system. Within each of the levels above any design method might be
applied.
Ng and Stephanopoulos (1998b) propose to use a similar hierarchy for control structure design. The difference between Douglas (1988) and Ng and Stephanopoulos (1998b)’s hierarchy is that level 1 is replaced by a preliminary analysis and level 4 and on is replaced by more and more detailed structures. At each step the objectives identified at an earlier step is translated to this level and new objectives are identified. The focus is on construction of mass and energy balance control. The method is applied to the Tennessee Eastman case.