Cell formation

1. Visual inspection2. Parts classification and coding system3. Production flow analysis (PFA)

1. Visual inspection

• Least sophisticated & least expensive• Classification of parts into families by looking

at either the physical parts or photograph and arranging them into similar groupings.

2. Parts classification and coding system

• Grouping of parts into families involves an examination of the individual design and/or manufacturing attributes of each parts.

• The attributes of the part are uniquely identified by means of a code number.

• Coding system should be custom-engineered for a given company or industry.

• Coding system structure i. Hierarchical structure: interpretation of each succeeding

symbol depends on the value of the preceding symbols. ii. Chain type structure(polycode): interpretation of each

symbol in the sequence is fixed and does not depend on the value of preceding digits.

iii. Hybrid structure: combination of Hierarchical structure and Chain type structure.

Three parts classification and coding systems

• Opitz system• MICLASS system• CODE system

Opitz system

• Consists of nine digits, which can be extended by adding four more digits.

• The first nine digits convey both design and manufacturing data.• 12345 called “form code”-primary design attributes (main shape,

external-internal shape, m/cing of plane surface, other holes teeth and forming). • 6789 called “supplementary code”-(dimension, material, original shape

of raw material, accuracy). • ABCD called “secondary code”- (production type operation and

sequence).

12345 6789 ABCD

3. Production flow analysis (PFA)

• Machine usage sheet.• Route card information. Machine-part incidence data

Frequency table

Module 1- Machine 1 as nucleus

Module 2- Machine 13 as nucleus

Modules for the given matrix

Modules after merger