Medium Variety

Medium variety - medium production - 100 - 10,0000

Hard product

Soft Product

Batch Production

Cellular Manufacturing

Flexible Automation

Process Layout

Cellular Layout

Department for mills, lathes and drills

Make one batch - move to next product - make next batch

Production rate > demand, so can use the same equipment

Object is created stage by stage over a series of work stations, and different batches of product are made

Change over in physical setup and/or equipment is required between prodcuts

Change over = lost manufacturing time

Normally get repeat orders

Make to stock situations, replenish inventory that has been depleted by demand

Advantages / disadvantages

Advantages:

-Flow of materials and ability to use special equipment at each work station

-Flexibility to produce variety of products in different volumes

-Not vulnerable to equipment failures

Disadvantages:

-Less efficient as it accommodates a variety of tasks at a number of work stations - same as job shop

-More waiting time because of variations in processing time, batch size and set up time

-larger space requirements for in process inventory

-complex scheudling and

Based on Group Technology

Standardisation / similarity between parts

Group dissimilar machines or processes into cells

Each cell manufactures a:

-part

-product family

-limited group of families

Objectives:

-shorten lead times

-reduce work in progress-

improve quality

-simplify production scheduling

-reduce setup times

Advantages:

-reduce material handling

-more efficient scheduling

-reduced set up times

-reduce wait times

-less in process inventory space needed

Disadvantages:

-reduced shop flexibility

-possible reduction in machine utilisation

-machine layout need reorganisation

-complex scheduling

may have a mill, a grinder and a drill in each cell

-In GT, cells specialise in the production of a family

-Parts are classified through three methods

1)visual inspection

2)part classification and coding

3) production flow analysis

A part family is a collection of pars that have similiarites in:

1)Geometric shape and size

2) processing steps for manufacture

Benefits of GT

1) standardisation of tooling and fixtures

2) material handling = reduce

3) process planning = simplified

4) WIP and lead time = reduced

5) Improved work satisfaction + improved quality

Extension of programmable

dates back to the 1960's

Capable of producing a variety of parts

virtually no time lost for change overs

no lost time due to reprogramming

Processes soft products

high initial investment

summary:

-high investment

-continuous production of variable mixtures for products

-medium production rates

-flexibility to deal with design variations