Lean production systems are sometimes referred to as pull systems because demand from customers activates the production actions of the manufacturing facilities. In order for this demand to be communicated to everyone in the supply chain$/$manufacturing facility a signal must be passed from downstream processing centers to the upstream processing centers. This system of relaying signals is referred to as a:

a$.$

Keiretsu Network

b$.$

Kanban System

c$.$

Semaphore System

d$.$

TQM Networ