The principles presented here represent an accumulation of experience equivalent to untold years of practice. They are adapted from those stated in the literature, with certain changes made for clarification and with several new one added to round out the coverage of the field. In reviewing the principles it will be found that nearly every one applies to several aspects of Material Handling and aids in accomplishing one or more objectives.
1. Principle of Planning:
All Handling activities should be planned.
Description: If there is one principle on which all should agree, it is that handling activities should be planned, and not left to chance. Remember, Handling may account for 25 to 80 percent of all the productive activity. Management most certainly deserves to have this sizable portion of total activity planned – not left to chance.
Suggestions for carrying out the Planning Principle:
- Avoid placing material directly on the floor, without a pallet or other support underneath.
- Assure adequate storage space at the workplace for the proper amount of material, both ahead of and following the operation being planned.
- Plan to use the same container throughout the system; avoid frequent changes of containers.
- Consider floor Load capacities, ceiling heights, truss capacities, column spacing, etc.
- Apply the principle of Motion Economy
- Provide necessary clearances in and around each work place — for proper handling of materials and for maneuvering handling equipment.
- Arrange for instruction for each operator in the correct method.
- Plan for correct location of material supply and disposal in work in work area.
- Provide adequate means for scheduled scrap removal.
- Plan for productive operations and inspections to be done during material movement.
- Combine operation to eliminate intermediate handlings.
- Do make judicious use of Manual Handling.
- Plan to minimize walking.
2. Systems Principle:
Plan a system integrating as many Handling activities as is possible and coordinating the full scope of operations (receiving, storage, production, inspection packaging, warehousing, shipping, and transportation.)
Description: Each Handling activity should be considered a portion of the whole Handling system, and planned as an integral part of the system.
Suggestions for carrying out the Systems Principle:
- Consider the entire scope of the handling activity, i.e., beyond the area under immediate consideration.
- Plan flow between work areas.
- Integrate operations into the handling system, such as : processing , inspection , packaging , etc
- Arrange for alternative Handling Methods – in case of emergency.
- Move material directly to production whenever practical, rather than an intermediate storage area- to avoid re-handling.
- Work closely with suppliers, customers and carriers.
- Be aware of future requirement changes in product, process, volume, etc. and allow for necessary flexibility.
3. Principle of Material-Flow
Plan an operation sequence and equipment arrangement to optimize material flow.
Description: The Material-flow pattern is actually the backbone of most production facilities, and one of the first steps in Planning a Material Handling systems is the design of the Material- flow pattern. This may be largely determined by operation sequence, which in turn will determine the pattern of equipment arrangement.
Suggestions for carrying out the Material-Flow Principle:
- Avoid crowded conditions.
- Eliminate obstacles from Material flow.
- Carefully observe building and carrier restrictions.
- Plan movement in direct path.(Avoid backtracking, zigzag flow, crooked paths.)
- Arrange for alternate path, in case of difficulty.
- Be aware of cross traffic and take necessary precautions. Avoid traffic Jams.
- Keep related work areas close together.
- Use Product-type layout when possible
- Plan proper location of sub assembly and feeder lines.
- Combine operations to eliminate handling between times.
- Plan for definite pickup and delivery locations.
- Minimize moves between Floors, Buildings.
4. Principle of Simplification
Reduce, combine, or eliminate unnecessary movements and /or equipment.
Description: Simplification is one of the by-words of efficiency, motion economy, and many other aspects of industrial operation. It should likewise be a goal in Material Handling. As used here, it implies, primarily, the reduction or elimination of moves as well as the elimination or reduction of equipment that is not being properly utilized.
Suggestions for carrying out the Simplification Principle:
- Apply the principle of motion economy.
- Reduce or eliminate long or complicated Moves.
- Plan direct moves.
- Deliver materials to correct location (spot) the first time.
- Avoid unnecessary Handling.
- Eliminate re-handling.
- Plan to use materials out of original container.
- Minimize number of moves per process.
- Minimize walking.
- Avoid use of variety of equipment types and / or makes.
- Provide proper number of containers.
- Plan for adequate equipment capacity.
- Do not mechanize for the sake of mechanization.
5. Principle of Gravity
Utilize gravity to move material whenever practicable.
Description: This is certainly a very obvious principle- but one that is all too frequently overlooked because of its simplicity. Many material moves can be made efficiently by proper application of the Law of gravity.
Suggestions for carrying out the Gravity Principle:
- Use Roller or wheel conveyors, slides chutes, etc., between operations.
- Use ramps between varying work or floor levels.
- Sloping floors (slight) can be utilized where considerable hand truck movement is in one direction.
- Use chutes to connect conveyors at different levels.
- Use spiral chutes to connect conveyors between floors.
6. Principle of Space-Utilization
Make optimum utilization of building cube.
Description: Factory and warehouse space are expensive. Therefore, wasted space is wasted money. Inherent in this principle is that both square feet and cubic feet are to be given consideration. One square foot contains as many cubic feet as “clear” height will permit items to be stacked.
Suggestions for carrying out the Space-Utilization Principle:
- Move equipment and operations closer together (not too close)
- Eliminate or condense “temporary” storage piles of materials
- Stack material to use full cube available.
- Use racks to permit higher stacking.
- Use stacking containers to permit stacking without racks.
- Analyze space utilization to “find” additional square or cubic feet.
- Check on economic order quantities and economic lot sizes for possibilities of reducing amount of material required on hand.
- Clean out storage areas and dispose of obsolete or useless materials.
- Use narrow-aisle handling equipment to permit reduction of aisle widths.
- Use Handling equipment not requiring fixed floor space , i.e., mobile or overhead Equipment.
- Don’t pile materials directly on floor – use pallets, skids , etc., to permit stacking.
- Consider reinforcing floors to permit heavier floor loads and stacking to greater heights.
- Use collapsible container to save space required by empties.
- Consider possibility of nesting parts products, containers.
- Review possibility of increasing inventory turnover.
- Design Pallets etc. to effectively utilize space between columns.
7. Principle of Unit-Size
Increase quantity, size, weight of load handled.
Description: Wherever practical, individual items should gathered and made up into loads.
Suggestions for carrying out the Unit-Size Principle:
- Examine every move of one item for possibility of making up unit loads.
- Purchase materials in unit loads.
- Work with vendors towards design of larger unit loads.
- Use containers to consolidate items.
- Use uniform, standardized containers.
- Design pallet pattern to efficiently utilize pallets and storage space.
8. Principle of Safety:
Provide for safe handling methods and equipment.
Description: It should be obvious that all handling activities in operations or being planned – should be safe, since an objective of material handling is to improve working conditions by providing safer work situations. A high proportion of all industrial accidents is in the material handling aspects of the production activity.
General causes of Industrial Accidents:
I) Unsafe Conditions, Environmental Causes.
- Inadequate guarding ( of Conveyors, Trucks, etc )
- Unguarded (equipment.)
- Defective condition (of equipment).
- Hazardous arrangement (stacks of material, pallet loads, arrangement of trucks, etc.
II) Unsafe Acts of Persons.
- Operating without authority (trucks, etc.)
- Operating at unsafe speed.
- Making safety devices inoperative (governors, etc.)
- Using unsafe equipment (needing repairs)
- Unsafe loading (machines, conveyors, cranes, trucks, etc.)
- Taking unsafe position or posture (in stacking, in trucks, etc)
- Working on moving equipment (trucks, conveyors, etc.)
III) Unsafe Personal Causes
- Improper attitude (taking chances, disregarding instructions)
- Lack of knowledge (poor instructions, new man, unskilled)
Suggestions for carrying out the Safety Principles:
- Install adequate guards and safety devices on handling equipment.
- Keep handling equipment in good operating condition.
- Furnish mechanical handling equipment for difficult, hard, hazardous handling activities and to handle dangerous materials.
- Do not permit handling equipment or devices to be overload or operated over rated capacity.
- Keep aisles clear and uncluttered .
- Install adequate lighting.
- Maintain floor in good condition.
- Avoid crowded conditions.
- Provide good house-keeping.
- Stacks material carefully.
- Be sure operation are properly instructed in method and / or use of equipment.
- Provide mechanized part feeding and removal devices,
- Plan for removal of undesirable dust fumes, smoke, etc.
- Isolate inherently dangerous equipment, operations etc.
- Allow Liberal factor of safety.
9. Principle of Mechanization/Automation
Use mechanized or automated handling equipment when practicable.
Description: Used judiciously, mechanized or automated handling devices and equipment can be of extreme value in increasing material handling efficiency. However, handling operations should not be mechanized for the sake of, mechanization alone, nor should they be over – mechanized in terms of the function to be performed.
Suggestions for carrying out the Mechanization/Automation Principles:
- Consider use of mechanization for:
- Large quantities or volume of materials
- Do not over mechanize.
- Design or select containers suitable for Mechanical Handling.
- Use equipment that is self controlled and self programmed when practicable .
- Consider mechanization of people flow and equipment movement as well as material movement.
- Mechanize communication to facilitate material movement.
- Utilize automatic couplings, switches transfer, etc.
10. Principle of Equipment Selection
In selecting Handling equipment, consider all aspects of the MATERIAL to be handled, the MOVE to be made, and the METHOD(s) to be utilized.
Description: This principle is primarily a reminder to be extremely careful in selecting & specifying handling equipment by being sure that all phases of the problem are thoroughly analyzed.
Suggestions for carrying out the Equipment Selection Principle:
- Select versatile equipment to carry out a variety of tasks and adjust to changing conditions.
- Select standardized equipment to avoid a multiplicity of makes and models – and to minimize inventory of repair parts.
- Prove that the move is necessary.
- Compare Cost on the basis of dollars per unit handled,
- Consider indirect or intangible factors in justifying investments.