Unit 2

FMS

Content• Introduction: FMS definition and classification of

manufacturing systems, Automated production cycle, Need of

flexibility, Concept of flexibility, Types of flexibilities and its

measurement.

• FMS Equipment: Why FMS, Factors responsible for the

growth of FMS. FMS types, its components, applications and

its benefits, Economic justification for FMS

Introduction

• FMS is the most automated and technologically sophisticated

manufacturing system applied in group technology cells.

• An FMS typically possesses multiple stations and is capable of

variable routing among stations. Its flexibility allows it to

operate in mixed model systems.

What is a flexible manufacturing system

• A flexible manufacturing system is a highly

automated GT machine cell, consisting of a group of

processing workstations (usually CNC machine tools),

interconnected by an automated material handling

and storage system, and controlled by a distributed

computer system.

FMS

Types of FMS

• A single Machine Cell• A flexible manufacturing cell• A flexible manufacturing system

Single Machine Cell

Flexible Manufacturing cell

Flexible Manufacturing System

Comparison

Flexibility

• A manufacturing system must posses three capabilities to be flexible:

• To identify and distinguish among the different incoming part or product styles processed by the system

• Quick changeover of Operating instructions• Quick changeover of physical setup.

Flexibility• To qualify as being flexible, a manufacturing system should satisfy

several criteria. The following are four reasonable tests of flexibility in an automated manufacturing system:

1. Part Variety test: Can the system process different part styles in a non-batch mode?

2. Schedule change test: can the system readily accept changes in production schedule, that is changes in part mix and/or production quantity?

3. Error recovery test: can the system recover gracefully from malfunctions and breakdowns, so that production is not completely disrupted?

4. New Part test: Can new part designs can be introduced into the existing product mix?

Flexibility

Flexibility Criteria Applied to the three types of manufacturing cell system

Two categories of Flexibility

A dedicated FMS : Produces a limited variety of part styles, A Random order FMS: It is more appropriate when part family is large,

there are substantial variation in part configurations, new part design will be introduced into the system and engineering changes will occur in p[arts currently produced, and the production schedule is subject to change from day to day.

FMS Components

• 1. Workstations• 2. Material Handling and storage system• 3. Computer control system• 4. People are required to manage and operate

the system.

1. Workstations

• Load Unload Stations: This is the physical interference between the FMS and the rest of

the factory. It is where the raw work parts enter the system and finished parts exit the system.

• Machining Stations: The most common applications of flexible manufacturing systems are machining operations. Most common is the CNC machining center.

• Other processing stations: In addition to machining other processes are there in FMS. Ex. Sheet metal fabrication such as punching bending shearing and forming etc.

1. Workstations

• Assembly: Some flexible manufacturing systems are designed to perform assemble operations. FMS gradually decreasing manual labor in assemble of product typically made in batches.

• Other Station and equipments: Online inspection can be incorporated into a flexible manufacturing system, either by including an operation at a processing work station or by including a station specifically designed for inspection.

Material Handling and Storage system

• Allows random, independent movements of work parts between stations.

• Enables handling of variety of workpart configuration.

• Provide temporary usage.• Provide convenient access for loading and

unloading workparts.• Creates compatibility with computer control.

Material Handling Equipments

• A primary handling system: responsible for moving parts in between stations in the system.

• The secondary handling system: it consists of transfer devices like automatic pallet changers, and similar mechanism available at the workstation of FMS.

FMS layout in According to Material Handling system

• In line layout• Loop layout• Ladder layout• Open field layout• Robot centered cell

Function performed by FMS computer control system

1. Workstation control2. Distribution of control instruction to workstations3. Production Control4. Traffic control5. Shuttle control6. Work piece monitoring7. Tool control8. Performance Monitoring9. Diagnostics