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According to APICS dictionary, the definition of protective
capacity is: "A given amount of extra capacity at non-
constraints above the system constraints capacity, used to
protect against statistical fluctuation ( breakdowns, late
receipts of materials, quality problems, etc.)." That is, the
protective capacity provides non-constraints with the ability to
"protect" throughput and due date performance.This thesis
applies float-time oriented scheduling method to set protective
capacity. It can cope with disruptions from three different
phases: (1)First phase: using float time to construct a robust
schedule; (2)Second phase: deriving the priority order for
control, according the float-time indexes; (3)Third phase: using
protective capacity to catch up the planned pace, when
disruptions occur. Thus, this method not only strengthens the
robustness of a schedule, but also offer a way of capacity
management that can be really functioned when the system is
suffered disruptions.The thesis also proposes the principles of
initiator's actions for using the protective capacity. The
principles include: How to identify non-constraints that need to
set protective capacity? When is needed? How to cooperate the
related resources? How to decide the level of protective
capacity? And when to exhaust the protective capacity?The
simulation results show that better performance is achieved on
both the cycle time and the work-in-process level when following
the principles of initiator's actions. This is done because that
the float-time oriented scheduling method ensures the production
of parts at right time, right quantity and right place.
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