Computer Integrated Manufacturing
Prentice Hall
Author: James A. Rehg / Henry W Kraebber
Pearson
Edition 3
Total pages 592
Pub.-date March 2004
Table of Contents
I. INTRODUCTION TO CIM AND THE MANUFACTURING ENTERPRISE.
1. The Manufacturing Enterprise.
Introduction. External Challenges. Internal Challenges. World-Class Order-Winning Criteria. The Problem and a Solution. Learning CIM Concepts. Going for the Globe. Summary. Bibliography. Questions. Problems. Projects. Appendix 1-1: The Benefits of a CIM Implementation. Appendix 1-2: Technology and the Fundamentals of an Operation-Authors' Commentary.
2. Manufacturing Systems.
Manufacturing Classifications. Product Development Cycle. Enterprise Organization. Manual Production Operations. Summary. Bibliography. Questions. Projects. Case Study: Evolution and Progress-One World-Class Company's Measurement System. Appendix 2-1: CIM as a Competitive Weapon.
II. THE DESIGN ELEMENTS AND PRODUCTION ENGINEERING.
3. Product Design and Production Engineering.
Product Design and Production Engineering. Organization Model. The Design Process: A Model. Concurrent Engineering. Production Engineering. Summary. Bibliography. Questions. Projects. Case Study: Repetitive Design.
4. Design Automation: CAD and PDM.
Introduction to CAD. The Cost of Paper-Based Design Data. CAD Software. CAD: Yesterday, Today, and Tomorrow. Application of CAD to Manufacturing Systems. Selecting CAD Software for an Enterprise. Product Data Management. Summary. Bibliography. Questions. Projects. Appendix 4-1: Web Sites for CAD Vendors. Appendix 4-2: B-Splines to NURBS. Appendix 4-3: Web Sites for Computer Companies.
5. Design Automation: CAE.
Design for Manufacturing and Assembly. CAE Analysis. CAE Evaluation. Group Technology. Production Engineering Strategies. Design and Production Engineering Network. Summary. Bibliography. Questions. Problems. Projects. Appendix 5-1: Ten Guidelines for DFA. Appendix 5-2: Web Sites for CAE Vendors. Appendix 5-3: Web Sites for Rapid Prototyping Vendors.
III. CONTROLLING THE ENTERPRISE RESOURCES.
6. Introduction to Production and Operations Planning.
Operations Management. Planning for Manufacturing. MPC Model-Manufacturing Resource Planning (MRP II). Production Planning. Master Production Schedule. Inventory Management. Planning for Material and Capacity Resources. Introduction to Production Activity Control. Shop Loading. Input-Output Control. Automating the Planning and Control Functions. Summary. Bibliography. Questions. Problems. Projects. Appendix 6-1: Priority Rule System.
7. Detailed Planning and Production-Scheduling Systems.
From Reorder-Point Systems to Manufacturing Resource Planning (MRP II). Material Requirements Planning. Capacity Requirements Planning. Manufacturing Resource Planning. Features of Modern Manufacturing Planning and Control Systems. Summary. Bibliography. Questions. Problems. Projects. Appendix 7-1: Wright's Bicycle Example. Appendix 7-2: ABCD Checklist. Appendix 7-3: An ERP Example Using WinMan.
8. Enterprise Resources Planning, and Beyond.
MRP II: A Driver of Effective ERP Systems. Information Technology. The Decision to Implement an ERP System. Identifying ERP System Suppliers. Developing Technologies: Converging and Enabling. Integrating Systems to Manage Design Data. Summary. Bibliography. Questions. Projects.
9. The Revolution in Manufacturing.
Just-in-Time Manufacturing. Synchronized Production. The Emergence of Lean Production. Modern Manufacturing Systems in a Lean Environment. Summary. Bibliography. Questions. Projects. Case Study: Production System at New United Motor Manufacturing, Part 1. Case Study: Production System at New United Motor Manufacturing, Part 2.
IV. ENABLING PROCESSES AND SYSTEMS FOR MODERN MANUFACTURING.
10. Production Process Machines and Systems.
Material and Machine Processes. Flexible Manufacturing. Fixed High-Volume Automation. Summary. Bibliography. Questions. Projects. Appendix 10-1: History of Computer-Controlled Machines.
11. Production Support Machines and Systems.
Industrial Robots. Program Statements for Servo Robots. Programming a Servo Robot. Automated Material Handling. Automatic Guided Vehicles. Automated Storage and Retrieval. Summary. Bibliography. Questions. Projects. Case Study: AGV Applications at General Motors.
12. Machine and System Control.
System Overview. Cell Control. Proprietary Versus Open System Interconnect Software. Device Control. Programmable Logic Controllers. Relay Ladder Logic. PLC System and Components. PLC Types. Relay Logic Versus Ladder Logic. Computer Numerical Control. Automatic Tracking. Network Communications. Summary. Bibliography. Questions. Projects. Appendix 12-1: Turning G Codes.
13. Quality and Human Resource Issues in Manufacturing.
Quality Foundations. Total Quality Management. Quality Tools and Processes. Defect-Free Design Philosophy. The Changing Workforce. Self-Directed Work Teams. Summary. Bibliography. Questions. Projects.
http://www.engr.sjsu.edu/sobi/Tech%20180B%20Readings.htm
This article is based on the summary made by Dr. Samuel C. Obi. I am trying to modifying and linking various articles that I already wrote on industrial engineering and manufacturing management. Many of the issues discussed in this summary are relevant to Production Industrial Engineering a subject that I am now proposing.
Introduction to CIM Technology
Objectives:
a) Describe the nature of computer integrated manufacturing enterprise
b) Define computer integrated manufacturing (CIM)
c) Develop an understanding of the basic components of CIM
d) Develop an understanding of the goals and objectives of CIM
e) Explore various manufacturing practices and the various issues related to the application of CIM
Rehg & Kraebber, Chapter 1: The manufacturing Enterprise
Introduction:
· Manufacturing enterprise is a collection of interrelated activities that includes product design and documentation, material selection, planning, production, quality assurance, management, and marketing of goods
· The fundamental goal of the enterprise is to use these activities to convert raw materials into finished goods on a profitable basis
·
· To be successful, a manufacturer must meet two challenges: external and internal challenges
External Challenges result from:
Niche market entrants, traditional competition, suppliers, partnerships and alliances, customers, global economy, cost of money, and the Internet
Internal Challenges result in:
A plan, process, or manufacturing strategy that forces congruence between the corporate objectives and marketing goals and production capability of a company
Order-winning criteria:
Defined as the minimum level of operational capabilities required to get an order. They include:
Price
Quality
Delivery speed
Innovation ability
Changing the product life cycle:
Kiazen or improvement of current model
Leaping or developing a new product similar to the initial product
Innovation or using genuine new product invention to identify follow-up merchandise
Order-winning versus order-qualifying criteria:
Market share is increased when the order-winning criteria are understood and executed better than the competition
Meeting the internal challenge:
Analyze every product and agree on the order-qualifying and order-winning criteria for the product at the current stage in it’s life
Project the order-winning criteria for the future stages in every product’s life
Determine the fit between the required process capability and the existing capability in manufacturing
Change/modify the marketing goals, or upgrade the manufacturing processes and infrastructure to force internal consistency
World-class order-winning criteria:
Setup time or time required to get a machine ready for production
Quality or % of defective parts produced or % of total sales
Manufacturing space ratio or a measure of how efficiently manufacturing space is utilized
Inventory: Velocity/residence time
Flexibility or a measure of the number of different parts that can be produced on the same machine
Distance or total linear feet of a part’s travel through the plant from raw material in receiving to finished products in shipping
Uptime or % of time a machine is producing to specifications compared to total time that production can be scheduled
Computer-integrated manufacturing defined:
CIM is the integration of the total manufacturing enterprise through the use of integrated systems and data communications coupled with new managerial philosophies that improve organizational and personal efficiency
Learning CIM concepts:
Process segments
Going for the Globe:
The CIM process: Step 1 (assessment of the enterprise in technology, human resources, and systems)
The CIM process: Step 2 (simplification or elimination of waste)
The CIM process: Step 3 (implementation with performance measures)
Free Market Economy Defined
An economic system in which the production and distribution of goods and services is not controlled by the government, but rather takes place through the mechanism of free markets which is guided by a free price system
Production-Oriented Activities In A Free Market Economy
Sales and marketing
Design
Production engineering
Manufacturing
Manufacturing personnel should be flexible and mobile
There is a need to learn cultures that are different from ours
Locality’s manufacturing programs should be more functional relative to area’s needs
Employ an interdisciplinary approach to make programs more agile and adaptable
Rehg & Kraebber, Chapter 2: Manufacturing Systems
Manufacturing system classifications:
Project
Job shop
Repetitive
Line
Continuous
Production strategy classification:
Relative to customer lead time
Relative to manufacturing lead time
Manufacturing lead time and customer lead time must be matched
Categories of production strategies used to match customer and manufacturing lead times:
Engineer to order (ETO)
Make to order (MTO)
Assemble to order (ATO)
Make to stock (MTS)
Product development cycle:
New product development
Existing product changes
Enterprise organization:
A successful CIM implementation requires an understanding of the functions performed by each block of an enterprise. They include:
Sales and promotion
Finance and management
Product/process definition
Manufacturing planning and control
Shop floor
Support organizations
Manual production operations:
Activity enters system as either a design or request for engineering action
Product design uses CAD to make the drawing
The product definition group lists the different parts of the drawing as BOM
The manufacturing definition group separates the BOM into those to be purchased and those to be manufactured inside
Manufacturing process planning determines the type of machines and process sequences required to process the parts
The business production planning produces the production schedule
Implementing a CIM system enhances and automates the above manual production operations
What is CIM?
C + I + M
C = Computer
It is an i. Enabling tool. It facilitates ii. Information flow
iii. Information management
I = Integrated
i. Integration vs. interfacing
ii. Shared information
iii. Shared functionality
M = Manufacturing
i. Production control
ii. Production scheduling
iii. Process design
iv. Product design
v. Manufacturing enterprise
Different definitions for different users
i. Shop communications
ii. Recurring processes
iii. Non-recurring processes
iv. Engineering/manufacturing communication
v. Other users
vi. Improving communication through CIM
Computer Integrated Manufacturing
A) Computer Integrated Manufacturing (CIM) systems technology refers to the technology, tool or method used to improve entirely the design and manufacturing process and increase productivity, to help people and machines to communicate. It includes CAD (Computer-Aided Design), CAM (Computer- Aided Manufacturing), CAPP (Computer-Aided Process Planning, CNC (Computer Numerical Control Machine tools), DNC (Direct Numerical Control Machine tools), FMS (Flexible Machining Systems), ASRS (Automated Storage and Retrieval Systems), AGV (Automated Guided Vehicles), use of robotics and automated conveyance, computerized scheduling and production control, and a business system integrated by a common database. (Houston Cole Library)
B) Computer Integrated Manufacturing (CIM) is the process of automating various functions in a manufacturing company (business, engineering, and production) by integrating the work through computer networks and common databases. CIM is a critical element in the competitive strategy of global manufacturing firms because it lowers costs, improves delivery times and improves quality. (Amatrol)
Potential Benefits of CIM
Shorter time to market with new products
Increase in manufacturing productivity
Shorter customer lead times
Improved quality
Improved customer service
Shorter vendor lead times
Reduced inventory levels
Greater flexibility and responsiveness
Lower total cost
Great long - term flexibility
UNIT 2: COMPONENTS OF COMPUTER INTEGRATED MANUFACTURING
Objectives:
a) Explore the design, nature and relationships of CIM sub-systems
b) Develop an advanced understanding of CIM sub-systems
c) Describe activities performed in each CIM sub-system
d) Determine the nature of enabling technologies behind each CIM sub-system
e) Relate the concept of CIM to a manufacturing enterprise’s model
Rehg & Kraebber: Chapter 3: Product Design and Production Engineering
Product design and production engineering:
These areas or departments are appropriate starting points for a detailed study of CIM
The two have embraced and encouraged the use of technology to reduce many tedious manual tasks
The initial creation of data starts in these areas
It is appropriate to have a common data base for all the data
Organizational Model:
Design information flow
The product area is responsible for product design and analysis, material selection, and design and production documentation
The production engineering area adds production standards for labor, process, and quality to the product data from design area.
Engineering release is responsible for product change control.
The design process: A model:
· Although there is a five-step design process, marketing plays a role before design engineering picks up
· Form (shape, style, and character), fit (marketing fit or order winning criteria), and function are determined with data from marketing department
Step 1: Conceptualization (recognition of need & definition of the problem)
Divided into two: Typical and atypical
Typical design relates to repetitive design
Atypical design is for new product
Step 2: Synthesis:
Specification of material
Addition of geometric features
Inclusion of greater dimensional details to conceptualized design
Removes (filters) cost-adding features and materials
Employs DFM and DFA to ensure good design
About 70% of manufacturing cost is fixed in steps 1 and 2 activities
Step 3: Analysis:
Analysis means determining/describing the nature of the design by separating it into its parts to determine the fit between the proposed design and the original design goals
Two categories of analysis are mass properties and finite
Can be performed manually, but the computer increases analysis capability and reduces its time
Step 4: Evaluation:
Checks the design against the original specifications
Often requires construction of a prototype to test for conformance
Often employs rapid prototyping technique
Documentation:
Creating all necessary product and part views in the form of working drawings, detailed and assembly drawings
Addition of dimensions, tolerances, special manufacturing notes, and standard components
Creation of part numbers, bill of materials, and detailed part specifications
Creation of product electronic data files used by manufacturing planning and control, production engineering, marketing and quality control
Concurrent Engineering:
Implies that the design of a product and the systems to manufacture, service, and dispose it are considered from the initial design concept
The traditional systems (process and disadvantages)
The new model for product design (participation in product deign broadens)
Automating the concurrent engineering process
Production Engineering:
Has the responsibility for developing a plan for the manufacture of the new or modified product.
Its seven areas of activities include process planning, NC/CNC programming, tool/fixture engineering, work & production standards, plant engineering, analysis for manufacturability and assembly, and manufacturing cost estimation
Concurrent engineering is used to bring production engineering activities together
Production Engineering Activities
Came across this process in Mallikarjuna Rao's Book. Page 69.
Process planning:
The procedure used to develop a detailed list of manufacturing operations required for the production of a part or product
Every part to be made has a routing sheet prepared
Routing sheets (also called process plans or operation sheets) describe the sequence of operations required to produce the finished product
The time data include setup time, unit run time, queue time etc.
The operation sheet also includes tooling, jig/fixtures needed, machines, operator skill levels and other key information needed.
In CIM environment, the operation sheet need not move with the part. The process information can be viewed on computer terminals
Production machine programming (NC, CNC and CAM)
Tool and fixture engineering:
Used to hold and position work while cutting
Request for this is made by production engineering
Tooling normally begins after the design is completed
Work and production standards:
Using direct time studies
Using motion and time measurement (MTM) or standard time data
Plant engineering (for the construction of a new facility when necessary)
Analysis for manufacturability and assembly
Design for manufacturing and assembly (DFMA)
Concept of DFX
Manufacturing cost estimation
Using manual approach
Using software packages
Rehg & Kraebber: Chapter 10: Production Process Machines and Systems
A part spends only 5% of the total time utilized for production on the machine
Only 1% is used for material removal
Load, unload and gauging take another 4% of the time
The majority of production time (95%) is divided among setup, moving, waiting, and inspection time
Production machines are producing nothing during setup, moving, waiting, load, unload and gauging times
Reducing these wasted times is the goal of world-class manufacturing
Material and machine processes:
Process operations are classified as:
Primary operations (converts raw material into basic geometry required for the finished product, e.g. casting, forming, sawing and oxyfuel and arc cutting)
Secondary operations (gives the raw material its final shape, e.g. turning, boring, milling, drilling, reaming, grinding and nontraditional machining processes)
Physical properties operations (changes physical properties but not the part geometry, e.g. heat treating)
Finishing operations, e.g. painting, plating, and etching/pickling
Flexible manufacturing. Flexibility refers to:
The number of different parts that a workstation can produce under normal production conditions
The ability to adapt easily to engineering changes in the part
The increase in the number of similar parts produced on the system
The ability to accommodate routing changes that allow a part to be produced on different types of machines
The ability to change the system setup rapidly from one type of production to another
Group technology focuses on the design of production cells to handle a family of parts with common production characteristics
Flexible manufacturing systems:
A group of NC machine tools that can randomly process a group of parts, having automatic material handling and central control to balance resource utilization dynamically so that the system can adapt automatically to changes in parts production, mixes, and levels of output.
An FMS is a collection of hardware linked together by computer software.
It includes NC and CNC machines, tooling and setup systems, part cleaning, deburring stations, material automatic storage and retrieval systems, CMM, and is linked by automatic material handling system such as robots, AGVs, and belt conveyors.
A minimum of five technology levels are present in an FMS:
Enterprise level for scheduling, programming, purchase orders and shipping documents
System level for coolant/chip, computer-controlled carts, downloading of codes, synchronization of cell operations, calibration and setup of tools, tool/material/finished goods inventory tracking
Cell level for machining cells, tool gauge and calibration station, material load and unload stations, testing and quality control cell, and part washing cell
Machine level for CNC machining centers, manual operations, AGVs, work holders and changers, quality testing machines, automatic parts washing machines, and tool interchange stations
Device level for sensors, ac and dc motors, pneumatic and hydraulic components, tools, fixtures, electrical components, connectors, wire, and fiber optics
FMC versus FMS:
An FMC is a group of related machines that perform a particular process or step in a larger manufacturing process
The production building blocks used to assemble an FMS are flexible manufacturing cells
Production machines can be a combination of manual and computer-controlled machines
Frequently, one operator runs two CNC machines, a process called two-to-one operation
Fixed high-volume automation:
Manufacturing systems capable of satisfying this type of production are called transfer machines or transfer lines
These large volume production systems are collectively called Detroit-type, fixed, or hard automation
Two types available: In-line and rotary fixed automation
OTHER MATERIALS
Changing Needs Call for New Methods
Complexity forces division of labor
Technology Growth
Availability of computers
NC programming
CAD systems
Databases
Need for data sharing
· Data Integrity
Current Capabilities and Applications
· Networks
· Hardware communications
· Embedded computers
· Systems integration
Problems to Overcome in Implementing CIM
· Interdepartmental support/politics
· CIM justification
· Intangible benefits
Additional Aspects of CIM
· Simulation
· Organizational awareness
· File management systems
· The “paperless factory”
· Features-based design systems
· Evolving standards (IGES, PDES, CALS)
· Concurrent engineering
Factory of the Future
Manufacturing Today
As islands of automation
Implementing automaton and the need for standards
The role of the computer in computer-integrated manufacturing
Managing change
Planning for the Factory of the Future
o The “as is” factory scenario
o The “to be” factory scenario
o JIT manufacturing
o GT manufacturing
o Types of manufacturing systems
o Automated material handling
o Scheduling system
o Control functions
o Machine tool requirements
o Unattended machine operation
Evolution of Manufacturing
· Manufacturing partnerships
o Role of the employee
o Customer and supplier roles
Unit 3: Computer Integrated Manufacturing Technology: (CAD & CAM)
Objectives:
a) Apply CIM concepts in the creation of an appropriate database
b) Develop product from CAD-CAM interface as CIM sub-systems
c) Describe the concept of computer numerical control programming as part of CIM
d) Describe the role of inventory control system in CIM environment
e) Generate and edit part programs using latest CAM software
f) Develop the concept of group technology as an aspect of CIM
REHG & KRAEBBER, CHAPTER 4: DESIGN AUTOMATION: CAD
CAD is the application of computers and graphics software to aid or enhance the product design from conceptualization to documentation.
Computer-aided drafting (CAD) automates the drawing or product documentation process.
Computer-aided design (CAD) is used to increase the productivity of the product designers.
CAD system capabilities include:
Stand-alone PC and RISC-based CAD workstations at each engineering and design drafting location
The ability to share part data and product information with every station in the system
Access to part data files from the mainframe computers on the network
Shared peripheral resources such as printers and plotters
Concurrent work on the same project from multiple workstations, one of the reasons our team project needs a web site or data base.
Basic CAD system includes:
Keyboard
Input devices
Output devices
Application of CAD to manufacturing systems:
Concept and repetitive design (product, fixtures, gauges, pallets, mold, etc.)
Drafting
New product development management (PDM) and the Internet
Rehg & Kraebber, Chapter 5: Design Automation: Computer-Aided Engineering
· Computer-aided engineering (CAE) is the analysis of the engineering design using computer-based techniques to calculate product operational, functional, and manufacturing parameters too complex for classical methods.
· CAE also provides productivity tools to aid production engineering area by providing software to support group technology (GT), computer-aided process planning (CAPP), and computer-aided manufacturing (CAM)
Design for manufacture and assembly (DFMA):
· DFMA is any procedure or design process that considers the production factors from the beginning of the product design.
· Originated from producibility engineering (DFM) and design for assembly (DFA)
Computer-aided engineering analysis:
· Finite-element analysis (most frequently used)
· Mass property analysis
Computer-aided engineering evaluation:
· Prototyping
o Rapid prototyping
§ Stereolithography
§ Solid ground curing
§ Selective laser sintering
§ Three-dimensional printing
§ Fused-deposition modeling
§ Laminated object manufacturing
Group Technology (GT):
· GT is a manufacturing philosophy that justifies small and medium-sized batch production by capitalizing on design and/or manufacturing similarities among component parts.
· Coding and classification:
o Coding is a systematic process of establishing an alphanumeric value for parts based on selected part features.
o Classification is the grouping of parts based on code values
o Coding and classification in GT are highly interactive because the coding system must be designed to produce classified groups with the correct combination of common features.
· In GT production cells, groups of different machines are identified based on their ability to produce families of parts.
Computer-aided process planning (CAPP):
· Consistent and correct process planning requires both knowledge of the manufacturing processes and experience.
· Two automation techniques are called variant and generative process planning.
· The CAPP variant approach uses a library of manually prepared process plans in the database and a retrieval system to match components on new parts to existing process pans of similar components.
· The CAPP generative approach utilizes a process information knowledge base that includes the decision logic used by expert human planners.
Computer-aided manufacturing (CAM):
· CAM is the effective use of computer technology in the planning, management, and control of production for the enterprise.
· One of the major applications of CAM is in CAD/CAM where the part geometry created with CAD in the design engineering is used with CAM software to create machine code (NC/CNC) capable of machining the part.
· Production and process modeling
· Production and process simulation
· Production cost analysis
Design and production engineering network demands:
· A common database for enterprise information flow
· Easy, accurate and instantaneous movement of part geometry files and product data between departments
· An enterprise network is a communications system that supports communications and the exchange of information and data among various devices connected to the network over distances from several feet to thousands of miles
Review and Other Materials
Manufacturing Product Planning
· Market Research and Forecasting
· Product Design
o Expert systems
o Design considerations
· Group Technology (GT)
o Reasons for adopting GT
o Benefits of GT
§ Benefits in product design
§ Standardization of tooling and setup
§ More efficient material handling
§ Increased economies of batch-type production
§ Easier scheduling
§ Reduced work-in-process and lead time
§ Faster and more rational process planning
Production Engineering
· Manufacturing engineering
Process planning engineering
The planning process
Process planner qualifications
Automation of process planning
Geometric tolerance stacking
o Tool design engineering
o NC programming engineering
· Industrial engineering
Computer Fundamentals
· Microcomputers
· Minicomputers
· Mainframe computers
· Distributed processing
Computer Numerical Control
· Control features
o Types of interpolation (linear, circular, helical & parabolic)
o CSFM programming
o Parametric programming
o Digitizing programming
o Centerline programming
o Adaptive control
o Over travel monitoring
o Mathematical capability
· Management features
Distributive Numerical Control (DNC)
· Conventional system
· CNC “behind the reader” system
· DNC minicomputer system
Integrated Machine Tool Control Systems
· Communication protocols and MAP
· Factory floor networks
· Cell controllers
UNIT 4: MANUFACTURING PLANNING, CONTROL AND SCHEDULING IN CIM ENVIRONMENT
Objectives:
a) Develop a general understanding of manufacturing planning and control in a CIM environment
b) Employ scheduling strategies employed in a CIM enterprise
c) Describe inventory management techniques as applied to CIM
d) Explore different forecasting techniques used in modern manufacturing
e) Describe quantitative methods, software applications, and financial management employed in a CIM environment
REHG & KRAEBBER, CHAPTER 6: INTRODUCTION TO PRODUCTION/OPERATIONS PLANNING
The planning functions have formal interfaces with both the design and production departments and informal relationships with most of the enterprise. The operations management functions are a critical part of the CIM implementation.
Operations management:
Has the responsibility for the administration of enterprise systems used to create good or provide services.
For example, the factory management must design new products, redesign current models, test designs, order raw materials, determine product mix and quantity to produce, schedule the production machines, maintain production hardware and software, and adjust fixed and variable resources to meet changes in the market.
Manufacturing planning and control:
All planning has a time horizon, e.g. number of days, months or years
Enterprise planning is divided into three levels
The strategic plan is generally long range: one year to many years
The strategic plan is performed at highest level in management
The aggregate plan has an intermediate-length time horizon of about two to eight months
The aggregate plan emphasizes levels of employment, output, inventories, back orders, and subcontractors
The goal of aggregate planning is the generation of a production plan that utilizes the enterprise resources efficiently to meet customer demand
The production plan and forecasted customer demand provides the aggregate information from which the disaggregate master production schedule (MPS) is produced
The development of MPS data is the start of disaggregate planning
The disaggregate plan provides short-range planning with detailed plans that include machine loading, part routing, job sequencing, lot sizes, safety stock, and order quantities.
The disaggregate plan has the shortest time horizon
o The term disaggregate means to separate into component parts
At disaggregate planning level, an aggregate plan is disaggregated into all the various models and options necessary to meet customer demand
The first step in disaggregation is the creation of MPS from the aggregate production plan
The material requirement planning (MRP) strategy in the manufacturing planning and control (MPC) system is a very useful tool at the disaggregate level
MRP system addresses the need for parts management of complex products and product mixes with high rates of production
MRP process starts with the MPS providing the quantity of each model or part required (gross requirement) per period
The bill of materials (or BOM in the form of product structure diagram) and current inventory provide critical information for an effective MRP system
The product structure diagram illustrates clearly the sequence required to build the product, with the 0 level representing the finished product
The bill of materials provides the MRP system with the part number and quantity of all parts required to build and assemble the product
The inventory control system supplies the MRP system with the projected on-hand balance of all parts and materials listed on the BOM
The MRP run produces the requirements for purchasing and production that are needed to complete the master schedule
Part routing, lead times and capacity planning:
· The routing sheet specifies each production operation and the work center location
· Lead time includes four elements: run time, setup time, move time and queue time (setup time, move time and queue time add no value)
· Capacity requirement planning (CRP) works with the system data to calculate the labor and machine time requirements needed to complete the master production schedule
Production activity control:
· Production activity control or shop-floor control manages the detailed flow of materials inside the production facility
· It uses three different processes for scheduling production in manufacturing: Gantt charts, priority rules for sequencing jobs at work center, and finite loading
· Finite and infinite loading techniques are similar to daily production schedule process
Rehg & Kraebber, Chapter 7: Detailed Planning and Production-Scheduling Systems
· The manufacturing planning and control (MPC) process in the CIM enterprise is responsible for the aggregate and disaggregate planning of production and scheduling of manufacturing resources
· The aggregate plan starts with a production plan stated in broad product specifications
· The first disaggregate plan, broken into specific product models, is called the master production schedule (MPS)
· The MPS states the production plan for each model for several production periods in the MPS record
· The output of the MPS record provides the data for the material requirements planning (MRP) scheduling system
· Much of the contents of this chapter was covered in Tech 147
Rehg & Kraebber, Chapter 8: Enterprise Resource Planning and Beyond
· APICS Dictionary defined enterprise resource planning (ERP) as a method for the effective planning and control of all resources needed to take, make, and account for customer orders in a manufacturing, distribution, or service company
· ERP is one of the newer system concepts that focuses on the integration of business systems
· These integrated systems support all of the functional departments in the enterprise: sales and order entry, engineering, manufacturing, finance and accounting, distribution, order planning and execution, and the supply chain flow
· Tech 149 team project can take advantage of this philosophy in its concurrent engineering approach
· Since businesses are increasingly focusing on customers, customer relationship management (CRM) systems are being developed to help companies manage the information they have about their customers, the products these customers buy, and the way the customers prefer to do business
· Some related aspects of ERP include:
o Product data management (PDM)
o Information technology issues (data collection issues and system integration problems)
o The role of the internet
o Sample ERP systems include: PeopleSoft, SAP R/3, Oracle, Sterling, Legacy, and JBA (see page 337)
Rehg & Kraebber, Chapter 9: The Revolution in Manufacturing
· Several technologies and philosophies have revolutionized manufacturing in recent years. Some of these are covered in this chapter
Just-In Time (JIT) Manufacturing:
· Just-In-Time manufacturing (JIT) encompasses every aspect of manufacturing, from design engineering to delivery of the finished goods, and includes all stages in the processing of raw material
· JIT is much more that material-ordering plan that schedules deliveries at the time of need
· JIT focuses on the elimination of the seven wastes found in manufacturing practices, namely:
1. Waste of overproduction
2. Waste of waiting
3. Waste of transportation
4. Waste of processing
5. Waste of stocks
6. Waste of motion
7. Waste of making defective products
· Elements of JIT include:
o Technology management
1. Structured flow manufacturing
2. Small lot production
3. Setup reduction
4. Fitness for use
o People management
1. Total employee involvement
2. Control through visibility
3. Housekeeping
4. Total quality focus
o Systems management
1. Level load and balanced flow
2. Preventive maintenance
3. Supplier partnerships
4. Pull system
Kanban (Card):
· Kanban is a Japanese word that means “card”
· These cards in effect replace all work orders and inventory move tickets
· Within the MPC system, kanban controls the flow of production material
· One- and two-card kanban systems are in common use
· Kanban supports a pull (JIT) system
Drum-Buffer-Rope System
Lean Production
Other Related Materials:
Material requirements planning:
· Understanding the MRP record: Some definitions:
o Period number (time duration used in MRP planning process; one period represents a day, week, or month)
o Part number (identifies the specific part being planned for)
o Gross requirements (equals the anticipated future demand for an item per period)
o Scheduled receipts (all orders released to manufacturing or to suppliers through purchase orders)
o Projected on hand (the calculated inventory for the item projected through all the periods on the record)
o Planned order receipts (indicate when a planned order would be received if the planned order release date is exercised)
o Planned order releases (the suggested order quantity, release date, and due date generated by using MRP software)
o Lead time (time between release of an order and the completion or delivery of the order)
o Lot size (the required minimum order quantity determined by the economics of the production process)
o Safety stock (the lowest level of inventory allowed in the projected on-hand line; protect against variations in delivery
MRP calculations
· The product structure diagram and the MRP record:
o The MPS is used to determine the MRP gross requirement quantities in each period
o Every box in the product structure diagram is covered by an MRP record
o The MRP records are linked
o The planned order releases from one record flow into the gross requirements of the record at the next lower level
The benefits of MRP:
· Improved customer service
· Reduction in past due orders
· Better understanding of capacity constraints
· Significant increases in productivity
· Reduction in lead time
· Reduction in the inventory for finished goods, raw materials, component parts, and safety stock
· Reduction in work-in-process (WIP)
· Elimination of annual inventory
· Significant drops in annual accounting adjustment for inventory problems
· Usually, a doubling of inventory turns
· MPC has responsibility for the planning and control of the shop floor, production materials, production scheduling, quality process, and facilities planning
· MPC performs two distinct functions: 1) Manufacturing planning, and 2) Manufacturing control
Planning in the MPC:
· High-level planning for the business
· Forecasting future demand
· Planning for production
o Chase production strategy
o Level production strategy
o Mixed production strategy
o The MPS technique
o MPS time-phased record
o The MRP technique
o Inventory management (raw materials, component parts, work-in-process, or finished goods and products)
Product data management:
· Bill of materials
o Originates from design
o Includes quantity, part number, and specifications of each part
o Parts are either manufactured or purchased
o Represented in MPC as product structure diagram or indented BOM
Unit 5: Automated Manufacturing
Objectives:
a) Apply industrial controls, programmable logic controllers, and industrial robots in a CIM environment
b) Describe the theory of operation, programming, and the practical application of PLCs and robots
c) Describe fundamentals of data communications and local area networks as they relate to the various levels of communications between shop floor computers, PLCs, robots, CNC machine tools and automatic identification equipment
d) Integrate commonly used industrial control devices, including CAD/CAM, computer-assisted numerical control programming, computer-assisted quality control, and automatic identification
· Reasons for automation in the factory include:
o Reduced labor costs
o Sales growth
o Better quality
o Reduced inventory
o Increased worker productivity
Two types of automation are fixed and flexible systems
Current factory technology includes:
o Computer networks including ERP
o Data collection and reporting
o Automated material handling
o Cells and work centers
o Automated inspection and testing
o The paperless factory
o Robots
REHG & KRAEBBER, CHAPTER 11: PRODUCTION SUPPORT MACHINES AND SYSTEMS
Industrial Robots:
A robot is an automatically controlled, programmable, multipurpose, manipulating machine with several programmable axes, which may be either fixed in place or mobile for use in industrial automation applications.
Key word are reprogrammable and multipurpose
The basic robot system consists of manipulator, power supply, controller, end effectors, interfacing or required equipment such as devices and sensors and any communications interface that is operating and monitoring the robot, equipment and sensors
The mechanical arm is driven by electric motors, pneumatic devices, or hydraulic actuators
Six motions are identified: Arm sweep, shoulder swivel, elbow extension, pitch, yaw, and roll.
Robotic arm geometry classification includes the following: Cartesian geometry, cylindrical geometry, spherical geometry, and articulated geometry.
End effector or end-of-arm tooling must be provided for robots to have production capability
The controller is a special-purpose computer with a central processing unit which controls the robot’s arm and the work cell in which it is operating.
Robots are programmed by keying in or selecting menu commands in the controller language, moving the robot arm to the desired position in the work cell, and recording the position in the program often with a teach pendant.
Programming methods include:
Active robot teaching (teach pendant)
Passive robot teaching (lead-through)
Off-line robot programming
Robot applications include: Material processing, material handling, and assembly and fabrication.
Selecting and justifying robot application requires a detailed design process and cost analysis.
Justifying a robotic system is performed using this model: [P = I/(S-E)]
Automated material handling:
Material-handling process for parts and raw materials should be automated only after every unnecessary inch of material transport distance has been removed from the production process.
The work simplification and analysis process that precedes the design and selection of material-handling automation starts with a diagram of the production flow, using process flow analysis symbol shown on page 461.
The transfer mechanism used to move parts between work cells and stations serves two main functions: 1) move the part in the most appropriate manner between production machines, and 2) orient and position the part with sufficient accuracy at the machine to maximize productivity and quality.
Automated transfer systems include:
Continuous transfer such as overhead monorail
Intermittent or synchronized transfer such as the walking beam transfer system
Asynchronous transfer or power-and-free systems as in conveyor and pallet system.
Automatic guided vehicles (AGV):
· An AGV is a vehicle equipped with automatic guidance equipment capable of following prescribed guide paths and may be equipped for vehicle programming and stop selection, blocking, and any other special function required by the system.
· AGV types include: Towing vehicles, unit load vehicles, pallet truck vehicles, fork lift vehicles, light load vehicles, and assembly line vehicles.
· AGV systems must perform five functions, namely: Guidance, routing, traffic management, load transfer, and system management.
· AGV systems must be justified based on the current and future material-handling requirements.
Automated storage and retrieval systems (AS/RS)
Materials to be stored and retrieved include: 1) raw materials, 2) unsold finished products, 3) production parts, 4) purchased parts and subassemblies used in the assembly of products, 5) rework and scrap that result from production operations, 6) spare parts for repair of production machines and facilities, and 7) general office supplies including tools and instruments.
AS/RS is a combination of equipment and controls that handles, stores, and retrieves materials with precision, accuracy, and speed under a defined degree of automation.
REHG & KRAEBBER, CHAPTER 13: QUALITY AND HUMAN RESOURCE ISSUES IN MANUFACTURING
Deming’s 14 points for management
Total quality management (TQM)
Quality tools and processes (for quiz 3)
OTHER MATERIALS
FMS Benefits
Producing a family of parts
Random launching of parts
Reduced manufacturing lead time
Reduced work-in-process
Reduced operator requirements
Expandability
Increased machine utilization
Reduced capital equipment costs
Responsiveness to change
Ability to maintain production
Product quality improvement
Reduced labor costs
Better management control
Components of the Flexible Manufacturing System
FMS workstations:
FMS for prismatic parts
FMS for rotational parts
Robots
Fixtures and pallets
Tooling
Operators
Inspection system
Coolant and chip handling systems
Cleaning stations
FMS off-line operations
Control station
· Material handling system:
o Parts delivery:
-Material handling outside the FMS
- Material handling inside the FMS
-Conveyor systems
-Cutting tool delivery
o Load/unload stations:
-Handling equipment
-Operator control
o Buffer storage
