After reading this article you will learn about:- 1. Introduction and Definition of Material Handling 2. Functions and Principles of Material Handling 3. Engineering and Economic Factors 4. Relationship with Plant Layout.
Introduction and Definition of Material Handling:
Starting from the time, the raw material enters the factory gate and goes out of the factory gate in the form of finished products, it is handled at all stages in between, no matter it is in the stores or on the shop floor.
It has been estimated that average material handling cost is roughly 20 to 60% of the total production cost and the ratio between the weight of handled material to produce an item and the weight of the finished item may vary between 40 to 50.
A component may be handled even 50 times or more before it changes to finished product. It, thus, becomes clear that the cost of production of an item can be lowered considerably by making a saving in the material handling cost.
Material handling involves the movements of materials, manually or mechanically in batches or one item at a time within the plant. The movement may be horizontal, vertical or the combination of horizontal and vertical.
Material handling emphasizes upon the need of installing efficient and safe methods and equipment for material handling. It has been found that 35 to 40% of the plant accidents are the results of bad methods of material handling.
Functions and Principles of Material Handling:
The two main functions of material handling section are:
1.To choose production machinery and assist in plant layout so as to eliminate as far as possible the need of material handling; and
2. To choose most appropriate material handling equipment which is safe and can fulfill material handling requirements at the minimum possible overall cost:
In general, the functions and principles of good material handling are as follows:
(a) Minimize the movements involved in a production operation,
(b) Using the principles of containerization, unit load or palletization, aim at moving optimum number of pieces in one unit.
(c) Minimize the distances moved, by adopting shortest routes.
(d) Employ mechanical aids in place of manual labour in order to speed up the material movements.
(e) Changes in sequence of production operations may be suggested in order to minimize back tracking and duplicate handling.
(f) Safe, standard, efficient, effective, appropriate, flexible and proper sized material handling equipment should be selected.
(g) Handling equipment arrangement should minimize distances moved by products and at the same time handling equipment should not interfere with the production line.
(h) Utilize gravity for assisting material movements wherever possible.
(i) Design containers, packages, drums etc., to economize handling and to reduce damage to the materials in transit.
(j) Material handling equipment should periodically be resorted to check ups, repairs and maintenance.
Engineering and Economic Factors of Material Handling:
The Engineering Factors taken into Consideration:
(a) The conditions of existing building and plant layout:
If a material handling system is to be formulated for an existing building and facility layout, one has to study various features of the building, like door locations and sizes, ceiling heights, roof and floor strengths, stairs, columns, and width of aisles, etc.
Unfavourable features may restrict the use of fast and most suitable material handling equipment. One has to strike a balance and decide which feature of the building or existing layout is to be kept as it is and which others can be modified to advantage.
(b) Production processes and equipment:
It involves the type of production equipment, processes, method of production, quantities of materials involved/in handling, sequence of operations, etc. On the basis of these factors an optimum system of material handling can be evolved or at least some factors can be modified to achieve a better material handling system.
(c) Nature of materials and products to be handled:
Much depends upon the nature of raw materials, materials in process, quantities to be handled and distances to be travelled by them. A flexible, safe, and economical material handling system is developed taking into consideration the conditions, fragility and bulk of the materials involved.
(d) The existing material handling equipment:
The usefulness and effectiveness of existing material handling equipment is evaluated from its performance of handling different products. If found necessary, additional material handling equipment are purchased to reinforce the material handling operations.
The cost of material handling equipment, operating costs, repair and maintenance costs, taxes, insurance and depreciation costs are considered for economic analysis. A material handling system with the lowest prospective cost is selected.
The operating costs are reduced by, purchasing flexible material handling systems, increasing the amount of material to be handled at one time, minimizing the idle time for the equipment, increasing speed of handling and by acquiring material handling equipment of standard design.
A material handling system is said to be economical if the cost of handling per unit weight of the material for a particular movement is minimum. Economy in material handling can be achieved by employing gravity aided movements, minimizing the distances of material travel, and by using such systems in which the product from the machine directly falls over material handling equipment (say a conveyor or chute) and is taken to its destination without any assistance from the machine operator.
Proper periodic inspection, repair and maintenance of a material handling equipment increases its life, adds to its reliability, smoothens the flow of material and economizes the production system.
Relationship between Material Handling and Plant Layout:
Material handling and plant layout are closely interrelated, and a reciprocal relationship exists between the two. An effective layout involves least material handling and less costly material handling equipments. It permits, material handling without any loss of time, with minimum delays and least back tracking.
The total number of movements and the distances moved in one movement are also considerably reduced in a properly designed plant layout. In a poorly planned layout, the aisle’s/sub-aisle’s widths or ceiling heights may not be sufficient to accommodate efficient material handling equipment; even if used somehow or other, the back tracking or duplication of material movements may not permit the material handling system to be economical.
On the other hand, an efficient material handling system helps building an effective plant layout around itself. Various departments are located such that the material handling is minimized. Space requirements are considerably reduced. Material movements are much faster and more economical. Bottlenecks and points of congestion are removed. Machines and workers do not remain idle due to lack of material. Production line flow becomes smooth.