When eating a western style meal, if the knives, forks, spoons, and plates are already set, the person who uses them and the person who positions them only has to use them or set them in that order.
If preparations for assembly operations or processing operations could be done in this manner, no defects would occur, there would be no accidents, and work could be done efficiently. Doing this sort of operation more quickly is the ideal of Seiton.
Important Points for Supplying and Positioning Parts:
1. Parts and materials should be supplied at the proper time to the point of operations.
2. Their positioning around the workers should be done so that workers do not have to switch item hand to hand or move distances.
3. They should be positioned so that workers do not mistake the attachment of a part or forget to attach a part.
4. They should be positioned so that they are easy to grasp and so that no injuries result.
5. Workers should be able to do tool setting.
Supplying and positioning according to part positioning rules:
In the case of assembly operations, be they done at a work table or in assembly-line system, the task of supplying parts and positioning parts at the place of assembly is an important key to smooth operations.
Choosing the system for supply of parts:
Generally, there are three types of supply systems for conveying parts to assembly workshop.
Single unit supply system:
The system which conveys one item at a time to place of use:
This system is used for large or heavy items. Stacking and transferring is kept to a minimum until assembly is completed. This type of assembly is stationary until assembly is completed. Quality checked on all materials must be done in preceding process ahead of time.
Set supply system:
Just as in a table setting, the parts necessary for assembling one item are arranged ahead of time on a work table or pallet. It may be necessary to arrange the parts for one or several items. Unit items which are an assembled unit of small parts can also be considered part of supply set.
Lot supply system:
Preparing nuts, washers, screws, and other small parts for a single unit or set supply system can be troublesome operation. Accordingly, these items are delivered in their boxes or bags directly to the assembly worker, who will take out the amount necessary.
Way of choosing supply system:
Each of the three supply systems has its own characteristics. The one chosen will depend on the objects to be handled. It is important, however, to consider other factors. These considerations are written up in chart from below. An important point in making improvements is to consider these factors as well as the objects to be handled when making Seiton system improvements.
Factors for selecting a Supply System:
Direct operation time:
Middle sized parts in which one can make improved by shortening direct operation time, should use the set supply system. For items which are used in large numbers, it would be very effective to make position improvements for shortening the distance of actions.
Line organization efficiency:
In order to raise the efficiency of line balancing, the workers in the preceding process should place the items for the subsequent process next to the main body … set supply system
Bring parts-setting operations into the line….. set supply system:
A double check system can be created with the single unit and set supply systems, by having both the supply worker and the assembly worker make quality checks.
Man-hours for preparation operation:
The lot supply system brings parts into the assembly workshop in the form in which they were delivered, so preparation operations are unnecessary. The opening of packages and setting of items, as in set supply, must be done ahead of time.
Conveyance device from parts warehouse:
Single unit and set supply seek to eliminate shifting. In these cases, the conveyor from the product warehouse to the assembly workshop should be unified or have automatic interlocking.
Space on conveyor side:
The lesser the items which are objects for lot supply, the neater the conveyor side will be.