SHOP FLOOR CONTROL AND INTRODUCTION TO FMS
1. Shop floor control.
The systems that accomplish the production planning, development of master schedule, capacity planning and materials requirement planning is called shop floor control.
Shop floor control is defined as a method of controlling the work in process in the factory.
2. Functions of shop floor control – SFC;
§ Priority control and assignment of shop orders
§ Maintain information on work in process for MRP.
§ Monitor shop order status information.
§ Provide production output data for capacity control processes.
3. Modules of SFC system;
§ Order release
§ Order scheduling
§ Order progress
Purpose of order release in SFC;
The purpose of order release module is to provide the necessary documentation that accompanies an order as it processed through the shop. These documents collectively called as shop packets.
Purpose of order scheduling in SFC;
The purpose of order scheduling is to make assignments of the orders to various machines in the factory. Order scheduling satisfies the first function of SFC. i.e. Priority control and assignment of work orders.
Function of order progress in SFC;
§ The order progress module performs the remaining three functions of SFC.
§ To provide data relative to work in process
§ Shop order status
§ Capacity control
4. Functions of a Data Management system;
§ Data vault and document management
§ Process and work flow management
§ Product structure management
§ Data classification and retrieval
§ Project management
§ Data communication and notification
§ Data transport
§ Data translation
§ Image services
§ System administration
5. Factory Data Collection System;
FDC system is used to collect data for monitoring order progress in SFC. The following are important data collected by the FDC system.
§ Number of products (piece counts) completed at a certain machine.
§ Number of parts scrapped (or) Number of parts reworked.
§ Direct labor time spent
§ Equipment breakdown.
6. Purpose of data collection system;
The purpose of the data collection system in shop floor control is to provide basic data for monitoring order progress.
In computerized SFC system the data are submitted to the order progress module for analysis and generation of work order status reports and exception reports.
7. Types of data collected from the shop floor;
§ Machine data,
§ Operator data,
§ Tooling data,
§ Data relating to jobs to be done,
§ Materials data,
§ Materials handling data,
§ Scheduling data,
§ Process planning data, and
§ Inspection data.
8. Data collection techniques in shop floor control;
§ Job traveler
§ Employee time sheet
§ Operation tear strips or punched cards included with shop packet
§ Centralized shop floor terminals
§ Individual work centre terminals
9. Computer process monitoring (Computer assisted data collection systems)
Computer process monitoring is a data collection system in which the computer is directly connected to the workstation and associated equipment for the purpose of observing the operation.
10. Components used to build a computer process monitoring system
§ Transducers and sensors,
§ Analog to digital converters (ADC),
§ Real time clocks, and
§ Other electronic devices
11. Configurations of computer assisted data collection systems
Or (Automated data collection system)?
§ Data logging systems
§ Data acquisition systems
§ Multilevel scanning
12. Types of data collection systems
§ On-line data collection systems
§ Off-line data collection systems
13. Data acquisition system ( DAS )
The data acquisition system that collects data from the various production operations for direct communication to a central computer. Hence it is called as online system.
14. Automatic identification methods.
Automatic identification is a term that refers to various technologies used in automatic or semi automatic acquisition of product data for entry into a computer system.
15. Technologies available for automatic identification system
§ Bar codes,
§ Radio frequency systems,
§ Magnetic stripes,
§ Optical character recognition, and
§ Machine vision.
16. Classifications of bar codes according to the dimensions of width
High density : X dimension is 0.010 in. or less.
Medium density : X dimension is between 0.010 and 0.030 in.
Low density : X dimension is 0.030 in. or greater.
17. Types of bar code readers
§ Fixed beam reader,
§ Moving beam reader.
18. Smart cards
§ Smart cards are made of plastic.
§ They are of the size of a credit card and are embedded with one or more microchips.
§ These have a 8 bit or higher level microprocessors and a storage capacity of about 8kB-256kB. Personal identification numbers prevent their unauthorized use.
19. Flexible manufacturing system – FMS;
A flexible manufacturing system consists of a group of processing stations, interconnected by means of a automated material handling and storage systems, and controlled by an integrated computer system.
20. Components of FMS systems;
§ Processing stations.
§ Material handling and storage.
§ Computer control system.
21. Different FMS layout configurations
§ Inline configuration,
§ Loop configuration,
§ Ladder configuration,
§ Open field configuration and
§ Robot centered cell.
22. Types of FMS
§ Flexible manufacturing module (FMM)
§ Flexible manufacturing cell (FMC)
§ Flexible manufacturing group (FMG)
§ Flexible fabrication-machining-assembly system (FFMAS)