We have discussed in previous sections the analysis of material flow and the design of layout based on it. We have referred to the selection of material handling equipment and area allocation for it. Materials handling is the art and science involving the movement, packaging and storing of substances in any form. In this section we will discuss about the objectives of the material handling system design, basic types of material handling systems and the procedure for the design and selection of material handling system while developing a plant layout.
Objectives and Functions
In order to perform the activities of materials handling the basic goal is to minimize the production costs. This general objective can be further subdivided into specific
Objectives as follows:
To reduce the costs by decreasing inventories, minimizing the distance to be handled and increasing productivity
- To increase the production capacity by smoothing the work flow
- To minimize the waste during handling-
- To improve distribution through better location of facilities and improved routing
- To increase the equipment and space utilization
- To improve the working conditions
- To improve the customer service
The analysis of materials handling requirements can be carried out by using travel charts and other quantitative techniques as outlined in section 7.5.
The basic materials handling function has to answer a number of questions as follows:
- Why do this at all? Justifying the necessity of material handling
- What material is to be handled? Giving the type (unit, bulk etc) Characteristics (shape, dimension etc.) and quantity
- Where and when? Specifying the move in terms of source and destination, logistics, characteristics (distance, frequency, speed, sequence etc.) and type (transporting conveying, positioning etc)
- How? And Who? Specifying the method in terms of the handling unit (load support, container, weight, number etc.), equipment, manpower, and physical restrictions (column spacing, aisle width, congestion etc)
Basic Materials Handling Systems
The different material handling systems can be classified according to the type of equipment used, material handled, method used or the function performed.
Equipment-Oriented Systems: Depending upon the type of equipment used, there are several systems.
- Overhead systems
- Conveyer systems
- Tractor trailer system
- Fork-lift truck and pallet system
- Industrial truck systems
- Underground systems
Material Oriented Systems: These may be of the following types.
- Unit handling systems
- Bulk handling systems
- Liquid handling systems
A unit load consists of a number of items so arranged that it can be picked up and moved as a single entity such as a box, bale, roll etc. Such a system is more flexible and requires less investment.
Method Oriented Systems: According to the method of handling and method of production, the material handling systems can be:
- Manual systems
- Mechanized or automated systems
- Job-shop handling systems, or
- Mass-production handling systems
Function Oriented Systems: The systems can be defined according to the material handling function performed as follows:
- Transportation systems
- Conveying systems
- Transferring systems
- Elevating systems
Selection and Design of Handling System
The selection and design of the material handling system should be done alongside the development of the layout as each one affects each other. Hence, an integrated approach to the design process is usable. A computerized technique known as COFAD (Computerized Facilities Design) has been developed for integrated handling system and layout design. The steps to be followed in the selection and design of handling systems are as follows:
- Identification of system
- Review of design criteria and objectives of the handling system
- Data collection regarding flow pattern and flow requirements
- Identification of activity relationships
- Determining space requirement and establishing material flow pattern
- Analysis of material and building characteristics
- Preliminary selection of basic handling system and generation of alternatives considering feasibility of mechanization and equipment capabilities
- Evaluation of alternatives with respect to optimal material flow, utilizing gravity, minimum cost, flexibility, ease of maintenance, capacity utilization and other objectives of the system design considering various tangible and intangible factors
- Selection of the best suited alternative and checking it for compatibility x) Specification of the system
- Procurement of the equipment and implementation of the system
