Assembly Lines

DVD

What the DVD Shows:

• History of operations management (OM) from 1910;

• How to arrange men, machines, materials, components in an operation;

• The essential role of OM;

• How OM has evolved: Issues OM focused on at different time.

How to Organize Manufacturing,Not How to Manufacture

• This DVD shows the state of art of organizing and managing process of manufacturing, instead of manufacturing technology.

• The ideas presented in this video can be extended to services

OM Topics Touched in DVD

• Productivity• Mass Production• Division of labor and interchangeable parts• Production process• Layout• Quality• Human factor• Flexible system and Lean system.

Adam Smith, 1723-1790

Assembly Line

• Each worker does a few pieces of simple tasks repeatedly;

• Workers stay at their workstations; Products are moved intermittently on a conveyer.

• A product stay with a workstation for a fixed time (cycle time), which was as short as 10 seconds.

Automobile Assembly Automobile Assembly ProcessProcess

A: Front-end body-to-chassis assembly

H: Hood attachmentF: Fluid fillingS: Start-up testing

Midsized

6 cylinder

A SH F

Midsized 6 cylinder

Figure 1.7

Henry Ford, 1863-1947

Characteristic of Assemble Line

• All products on conveyer move together;

• Workload of a workstation

<= Cycle time;

Bottleneck of Assembly Line

• The cycle time is limited by the slowest workstation;

• The line cannot start unless every workstation is ready;

• If one workstation is stuck (due to broken machine, bad quality, sick worker,...), whole line is stuck.

Effect of Assembly Line

• Lowered product cost;

• Raised quality;

• Increased productivity;

• Generating jobs.

Frederick W. Taylor, 1856-1915

Problems Occurred

• With increased line speed in Ford at early years of using assembly line, there came problems:– Workers were bored by doing simple tasks

repeatedly. But the company did not care what workers thought but the pace of line;

– More absentees, and high turnover rate.

• Solution of Ford (1920’s):– Raise worker’s salary.

Human Factor

• Raising salary solved the problem for a while, but not forever.

• Improved role of human after WWII:– Job enlargement;– Job enrichment;– Total quality management.

What Toyota Did in 1960’s – 1970’s

• Involve workers into operation process:– Value analysis;– Total quality control;– Just-in-time production;– Kanban system.

• Japan passed US in auto production and quality in 1980s.

Kiichiro Toyoda, 1894-1952

Response of US

• US auto industry responded:– Taking the approaches of OM which was

proved effective in Japan;– Computer aided design and manufacturing.

• The most flexible elements in production is “people”.