BRAINWAVE                                                     

“ARTICLE SHOWS THE WORKING OF AN EFFICIENT TOOL USED IN MANUFACTURING/PROJECT PLANNING WHICH HAS SCOPE OF BEING IMPLEMENTED IN EFFICIENT SCHEDULING IN ‘IT’ FIELD TOO.”

REVIEW: Group Technology is a new approach to production management, which seeks first to obtain similar economic savings in batch and jobbing production, to those already achieved using line flow in the simpler process industries, and in mass production, and second to provide a better type of social system for industry, in which improved labor relations are easier to achieve. Group technology is a manufacturing philosophy in which similar parts are identified and grouped together to take advantage of their similarities in design and production. Group technology is an approach to the organization of work in which the organizational units are relatively independent groups, each responsible for the production of the given family of products. The smallest organizational unit is the Group. Similar parts of a group are arranged into part families. Where each part family possesses similar designs are manufacturing characteristics. Grouping the production equipment into machine cells, where eah cell specializes in the production of part families, is called as cellular manufacturing. Cellular manufacturing is an example of mixed model production.

There are three primary steps in cellular manufacturing system:-

1)                  Cell formation

2)                  Machine Layout

3)                  Cell Layout

Code Systems: A code is a string of characters which stores information about a part. Using a coding system all the digits are assigned numerical codes, alphanumeric codes. Depending on how the digits of codes are linked, there are three coding systems: monocode, polycode and mixed code. Coding techniques are classified on the following basis:

1)      Functional Basis

2)      Structural Basis

Cluster Analysis: The objective of cluster analysis is to assign P parts to F part families while minimizing some measure of distance. The distance measure stored in a two dimensional array are accessed by a clustering algorithm to group the parts. There are number of methods that can be used for this purpose. Various grouping algorithms are used for this purpose. The grouping algorithms discussed in this paper are:

1)      Rank Order Clustering: Each row (column) in the part machine matrix is read as a binary word. The procedure converts these binary words for each row (column) into decimal equivalents. The algorithm successively rearranges the rows (column) iteratively in order of descending values until there is no change.

2)      Similarity Coefficient: There are wide latitude in the definition of the resemblance matrix and a choice of clustering method. A resemblance coefficient can be similarity or dissimilarity coefficient. The larger the value of similarity coefficient, the more similar the two parts or machines are; the smaller the value of a dissimilarity coefficient, the more similar the parts or machine are.

3)      Bond Energy Method:  It helps to identify and display natural variable groups or clusters that occur in complex data arrays. In this we find Measure of Effectiveness such that an array that possess dense clumps of numerically large elements are more uniformly distributed throughout the array.

Advantages of Group Technology over Conventional layouts:

Designing Groups:  The designing of groups takes place in three main stages. First it is necessary to decide on the policy for introduction, to define objectives, to plan the production system required to meet these objectives, and to make any changes in departmental organization which are needed before groups can be introduced. Second comes the identification of the components to be made and of the machines to be installed in each group. Finally it is necessary to plan the manning, management, layout and services for the groups and to plan any necessary changes in the supporting systems.                              

General Policy: Three main types of decisions to be made. These are concerned with:

1)      Preliminary Changes: it is possible to change to groups using existing machines or to extensively change the product design and production setup

2)      General approach to design and implementation:  four main methods are

·        Comprehensive analysis and comprehensive implementation

·        Comprehensive analysis and pilot implementation

·        Sample analysis and Pilot implementation

·        Sample analysis and comprehensive implementation

3)      Decision should be undertaken by Experts and senior directors of company

Defining objectives: before considering the problem of designing a group technology system, the objectives of the innovation should be defined and clearly stated.

Production system Specifications: the next step is to prepare a production system specification giving details of the group technology system as it should be after implementation.

Reorganization: reorganizing the departmental setup.

Finding groups: forming groups by different techniques.

Development of the group: further planning is needed to determine the manning levels required, the layout machines, tool storage and the methods of inspection and material handling.

Development of related systems: related systems of factory must be modified to get full advantage of Group Technology.

by Shivendra Pandey, MBA, IIITA.