ABSTRACT
Card-based control systems are input/output control systems. This means that they control the input of work in accordance with the output rate. Only if work leaves the shop floor is new work allowed to enter. The information on the output rate is typically provided by cards. This is why they are called card-based systems. While all four card-based control systems discussed in this book-kanban, constant work-in-process (ConWIP), pairedcell overlapping loops of cards with authorization (POLCA), and control of balance by card-based navigation (COBACABANA)—are indeed input/output control systems, there are significant differences in terms of how input/ output control is realized, i.e. the feedback loop. There are three dimensions to this:
1. The loop structure itself 2. The properties of the information that is circulated in the loop (i.e. the
cards)
3. The independence of the loops-i.e. whether additional IT support is required
In this, the concluding chapter, we will contrast our four card-based systems according to these three dimensions and explore the consequences in terms of their applicability to the different control problems.
