Module 1 - H Flashcards
bottleneck
A facility, function, department, or resource whose capacity is less than the demand placed upon it. For example, a machine or work center exists where jobs are processed at a slower rate than they are demanded.
buffer
1) A quantity of materials awaiting further processing. It can refer to raw materials, semifinished stores or hold points, or a work backlog that is purposely maintained behind a work center. 2) In the theory of constraints, these can be time or material and support throughput and/or due date performance. These can be maintained at the constraint, convergent points (with a constraint part), divergent points, and shipping points.
buffer management
In the theory of constraints, a process in which all expediting in a shop is driven by what is scheduled to be in the buffers (constraint, shipping, and assembly buffers). By expediting this material into the buffers, the system helps avoid idleness at the constraint and missed customer due dates. In addition, the reasons items are missing from the buffer are identified, and the frequency of occurrence is used to prioritize improvement activities.
capacity control
The process of measuring production output and comparing it with the capacity plan, determining if the variance exceeds pre-established limits, and taking corrective action to get back on plan if the limits are exceeded.
capacity-constrained resource (CCR)
A resource that is not a constraint but will become a constraint unless scheduled carefully. Any resource that, if its capacity is not carefully managed, is likely to compromise the throughput of the organization.
constraint
1) Any element or factor that prevents a system from achieving a higher level of performance with respect to its goal. Constraints can be physical, such as a machine center or lack of material, but they can also be managerial, such as a policy or procedure. 2) One of a set of equations that cannot be violated in an optimization procedure.
cycle time
1) In industrial engineering, the time between the completion of two discrete units of production. 2) In materials management, the length of time from when material enters a production facility until it exits.
dispatching
The selecting and sequencing of available jobs to be run at individual workstations and the assignment of those jobs to workers.
drum schedule
The detailed production schedule for a resource that sets the pace for the entire system. The drum schedule must reconcile the customer requirements with the system’s constraint(s).
drum-buffer-rope (DBR
The theory of constraints method for scheduling and managing operations that have an internal constraint or capacity-constrained resource
final assembly schedule (FAS)
A schedule of end items to finish the product for specific customers’ orders in a make-to-order or assemble-to-order environment. It is also referred to as the finishing schedule because it may involve operations other than the final assembly; also, it may not involve assembly (e.g., final mixing, cutting, packaging). The FAS is prepared after receipt of a customer order as constrained by the availability of material and capacity, and it schedules the operations required to complete the product from the level where it is stocked (or master scheduled) to the end-item level.
finite forward scheduling
An equipment scheduling technique that builds a schedule by proceeding sequentially from the initial period to the final period while observing capacity limits. A Gantt chart may be used with this technique.
finite loading
Assigning no more work to a work center than the work center can be expected to execute in a given time period. The specific term usually refers to a computer technique that involves calculating shop priority revisions in order to level load operation by operation.
five focusing steps
In the theory of constraints, a process to continuously improve organizational profit by evaluating the production system and market mix to determine how to make the most profit using the system constraint. The steps consist of (1) identifying the constraint to the system, (2) deciding how to exploit the constraint to the system, (3) subordinating all nonconstraints to the constraint, (4) elevating the constraint to the system, and (5) returning to step 1 if the constraint is broken in any previous step, while not allowing inertia to set in.
flow control
A specific production control system that is based primarily on setting production rates and feeding work into production to meet these planned rates, then monitoring and controlling production.
forward scheduling
A scheduling technique where the scheduler proceeds from a known start date and computes the completion date for an order, usually proceeding from the first operation to the last. Dates generated by this technique are generally the earliest start dates for operations.
idle capacity
The available capacity that exists on nonconstraint resources beyond the capacity required to support the constraint. Idle capacity has two components: protective capacity and excess capacity.
infinite loading
Calculation of the capacity required at work centers in the time periods required regardless of the capacity available to perform this work
input/output control (I/O)
A technique for capacity control where planned and actual inputs and planned and actual outputs of a work center are monitored. Planned inputs and outputs for each work center are developed by capacity requirements planning and approved by manufacturing management. Actual input is compared to planned input to identify when work center output might vary from the plan because work is not available at the work center. Actual output is also compared to planned output to identify problems within the work center
job shop scheduling
The production planning and control techniques used to sequence and prioritize production quantities across operations in a job shop.
manufacturing order
A document, group of documents, or schedule conveying authority for the manufacture of specified parts or products in specified quantities.
operations sequencing
A technique for short-term planning of actual jobs to be run in each work center based upon capacity (i.e., existing workforce and machine availability) and priorities. The result is a set of projected completion times for the operations and simulated queue levels for facilities
overlapped schedule
A manufacturing schedule that “overlaps” successive operations. Overlapping occurs when the completed portion of an order at one work center is processed at one or more succeeding work centers before the pieces left behind are finished at the preceding work centers.
priority control
The process of communicating start and completion dates to manufacturing departments in order to execute a plan. The dispatch list is the tool normally used to provide these dates and priorities based on the current plan and status of all open orders
