Input-Output Control
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Input-Output Control

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Work Centre Loading

Table of Content

Example of Input-Output Control

Input-output Control

What is Input-output Control ?
2.   Advantages of using Input-output Control
3.   Options
4.   Example of Input-output Control

5.   Demo Solution for the Example
6.   Try out the Input-output Control Exercise
7.   Comment on the Example and Input-output Control    

1.    What is Input-output Control      quespin.gif (22297 bytes)

                Input-output Control is a technique that allows operation to manage facility work          flow. It is used to control the size of the queues in front of work centres, thereby helping to          control manufacturing lead times. Refer to as "push system" of linking work centres. When a          batch of items is completed at one work centre, it is pushed to the next work centre, where it          waits in a queue until it is selected to be worked at that work centre.
                Input-output Control is important because it is a form of queue control, and a great
        portion of the time that a job spends in a plant is spent waiting in queues. In many job shops
        and batch manufacturing factories 80 to 95 percent of the total time is queue time.
        Input-output Control is used to monitor and control the amount if work in a queue at a work
        centre so that it stays within reasonable bounds. Queue times, therefore, are more consistent
        and predictable. The actual output, in standard hours of works, that flows from a work centre
        is the demonstrated actual capacity of the centre.
                If the capacity differs from the planned amount of work over a few scheduling periods,
        the problem needs to be investigated. If the work that flows to work centre is greater than the
        actual output, the queue in front of the centre will grow. On the other words, If the works is
        arriving faster than it is being processed, we are overloading the facility and a backlog
Overloading causes crowding in the facility, leading to inefficiencies and quality     
        problem. If the works is arriving at a slower rate than it is being performed, we are
        underloading the facility and the work centre may run out of work.
Underloading the facility
        results in idle capacity and wasted resources.

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2.    Advantages of using Input-output Control

Customer service may improve due to the items or products are produced on time.

Efficiency may be improved because of the less work-in-process in cluttering the work centre and adding to overhead costs.

Quality may be improved because less work-in-process hides fewer problems.
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3.    Options
The options available to operations personnel to manage facility work flow include :

Correction of performance.

Increasing facility size.

Increasing or reducing input to the work centre by:

                paw_yl.gif (125 bytes)    Routing work to or from other work centres.

                paw_pr.gif (128 bytes)    Increasing or decreasing subcontracting.

Example of Input-output Control   Example of Input-output Control

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    [What is Input-output Control]    [Advantages]   [Options]    [Example]