EWAB Pull and Re-route

Continuos Flow or “Pull And Re-Route”

To achieve continuos flow, a part that is on its way to the next operation must be given the option to choose an alternative parallel resource if the intended resource is not available. In manufacturing processes each resource must also be given the opportunity to access every part in the system without delay in order to avoid idle time. If assembly process, time variations related to product differences can vary more that what is allowed within the desired Takt time which means that alternative routing must be made possible.

With a self balancing interaction in-between the “pull” function and “re-route” function, EWAB Flow Technology can eliminate uncontrolled buffers, idle time in machines and increase throughput. This is the philosophy on which EWAB as a company is built. The very first systems built in 1970´s had this functionality and the philosophy has been implemented in all types of industries since then.

First In – First Out

The ideal situation is naturally to have a FIFO situation. Of practical reasons this can only be achieved in a straight sequential line and with a relatively low demand. This is often the case in assembly lines. In situations with high volume requirements (short Takt time), the sequential lines has to be duplicated which then reduces the overall FIFO level. In manufacturing processes where volume demand require machining operation with two or several parallel machines per process, FIFO can never be 100%. So in regards to FIFO one can only evaluate to what degree FIFO can be achieved.

Three types of buffers

If buffers are an element of the system they will further reduce the level of FIFO, depending on how the buffer works.

In-line buffers.

With In-line buffers, the part is still “in the flow” moving towards it’s destination. In traditional sequential conveyor systems the part may be caught up in a queue and be waiting for a long time.

Off-line buffers.

With Off-line buffers, the part is taken out of the flow and it becomes subject to the software controlling the system, to be returned into the flow. Off-line buffers are very difficult to control and should be avoided

Dynamic Buffer

EWAB Flow Technology can create a continuos flow system based on a third type of buffer, which we call Dynamic Buffer. It’s dynamic because the pull and re-routing functionality will minimise the time a part spends in a buffer situation thus improving the FIFO level considerably