MM 323 MANUFACTURING SYSTEMS PRODUCTION AND LAYOUT TYPES

MM 323 MANUFACTURING SYSTEMS PRODUCTION AND LAYOUT TYPES

THERE ARE TWO INDUSTRY TYPES THAT FACTORIES ARE LOCATED IN 1) Process industries, e.g., chemicals, petroleum, basic metals, foods and beverages, power generation Continuous production Batch production

2) Discrete product (and part) industries, e.g., cars, aircraft, appliances, machinery, and their component parts Continuous production (MASS PRODUCTION) Batch production

Production Facilities A manufacturing company attempts to organize its facilities in the most efficient way to serve the particular mission of the plant Certain types of plants are recognized as the most appropriate way to organize for a given type of manufacturing The most appropriate type depends on: Types of products made (in this course only DISCRETE) Production quantity per product type per year (Q) Product variety (N)

(Production Quantity per product type per year) must be high enough to recover FIXED COSTS. If we can find a product which has high production quantity per type (STANDART PRODUCTS), then we don t need to increase the product variety. Otherwise, to make the total production quantity HIGH enough to recover fixed costs and pay annual variable expenses we have to increase the variety which reduces similarity in the product types as we include more different types. QUANTITY PER PRODUCT TYPE IS CRITICAL. VARIETY DEPENDS ON PRODUCTION QUANTITY PER TYPE.

Production Quantity Number of units of a given part or product type produced annually by the plant Three quantity ranges: 1. Low production 1 to 100 units 2. Medium production 100 to 10,000 units 3. High production 10,000 to millions of units

Product Variety Refers to the number of different product or part designs or types produced in the plant Inverse relationship between production quantity and product variety in factory operations Product variety is more complicated than a number Hard product variety products differ greatly Few common components in an assembly Soft product variety small differences between products (MODELS) Many common components in an assembly

Product Variety vs. Production Quantity

Relationships between Plant Layout and Type of Production Facility

PRODUCTION AND LAYOUT TYPES Product Variety High JOB SHOP Process (Function) Layout Medium Low JOB SHOP Fixed Position (Location) Layout BATCH PRODUCTION Process (Function) Layout CELLULAR MANUFACTURING Group Technology (Cellular) Layout MASS PRODUCTION Product Layout (Production Line; Flow Shop; Assembly Line) Low Medium High Volume (Production quantity per product type per year)

I. Job Shop II. Batch III. Mass Production IV. Continuous Flow Low Volume, One of a Kind Commercial Printer French Restaurant Multiple Products, Low Volume Heavy Equipment Few Major Products, Higher Volume Automobile Assembly Burger King High Volume, High Standardization Sugar Refinery Flexibility (High) Unit Cost (High) These are the major stages of product and process life cycles Flexibility (Low) Unit Cost (Low)

Low Production Quantity JOB SHOP PRODUCTION TYPE makes low quantities of specialized and customized products Low volume production, often one of a kind Large variety of parts Small lot sizes Generally used for specific customer orders Flexible and general purpose equipment Flexible material handling (human-driven) Skilled workers Products are typically complex Examples: Space vehicles, aircraft, specialized machinery and machine tools, special tools, prototypes of future products Also includes production of components for these products In Job Shop Productıon Type two types of plant layouts are used: FIXED POSITION LAYOUT PROCESS (FUNCTION) LAYOUT

Fixed Position Layout

Fixed Position Layout lathe welding Raw materials PRODUCT press paint

Fixed Position Layout Production is executed at a fixed location; materials, equipment, and personnel flow into this location. This type of layout is usually required by the nature of the product Advantages Material movement is reduced An individual can complete the whole process Highly flexible; can accommodate any changes in design Disadvantages Personal and equipment movement is increased Risk of duplication of equipment Requires greater worker skills Not suitable for high production volumes

AN EXAMPLE FOR FIXED POSITION LAYOUT: Assembly operations on the Boeing 777

Process Layout

Process Layout STORAGE lathe lathe drill assemble assemble lathe drill assemble assemble assemble assemble mill mill grind paint paint mill mill grind paint paint mill

In PROCESS LAYOUT Similar/Same processes are grouped together. Advantages General purpose equipments can be used General purpose equipments are cheaper Robust against machine breakdowns Robust again design, volume changes Disadvantages Material handling requirements are increased Increased WIP Difficult to schedule the jobs Higher skills are required Difficult to analyze the process performance

Characteristics of Process Layouts Low Volume, High Variety Production with Random Routing (Spaghetti-Like Flow) General Purpose Machines-- Machine setups are frequent and long Work-In-Process -- High Throughput Rates tend to be Low Material Handling -- High Operator Utilization -- Low? Throughput Times (Lead Time) -- High System is Very Flexible, produces many different types of parts: gears, shafts, pinions, housings, clamps, etc.

Medium Production Quantities 1. Batch production A batch of a given product is produced, and then the facility is changed over to produce another product Changeover takes time setup time Typical layout process layout Hard product variety 2. Cellular manufacturing A mixture of products is made without significant changeover time between products Typical layout cellular layout Soft product variety

In Batch Production: Medium-sized lots of the same product Lots are often produced at regular intervals Generally used for continuous customer demand for a product General purpose equipment but designed for high production rate Examples: Machine shops, casting foundries, plastic molding factories, pressworking shops

Cellular Layout (MACHINE CELLS) 1)Part Families are formed. 2) Machines are grouped according to the processes required for part families. (MACHINE CELLS) 3) Each cell is in fact a production line for its part family and it becomes independent for detailed scheduling and control.

A machining cell consisting of two horizontal machining centers supplied by an inline pallet shuttle

High Production (MASS PRODUCTION) 1. Quantity production Equipment is dedicated to the mass manufacture of one/single product Standard machines tooled for high production (e.g., stamping presses, molding machines Punch presses, injection molding machines, automatic screwdrivers) Typical layout: process layout 2. Flow line production (automated flow lines, assembly lines) Multiple workstations arranged in sequence Product requires multiple processing or assembly steps Physical flow of products Typical Layout: Product layout (PRODUCTION LINE; TRANSFER LINE) is most common

In Mass Production: Continuous specialized production of identical products. Very high production rates Special purpose equipment, dedicated to one product Often entire plant is designed for the manufacture of a particular product Lower labor skills

In QUANTITY Production: Quantity production involves the mass production of single parts on fairly standard machine tools such as punch presses, injection molding machines, and automatic screw machines. Examples of items in quantity production include components for assembled products that have high demand rates (automobiles, some household appliances, light bulbs, etc.), hardware items (such as screws, nuts, and nails), and many plastic molded products.

In FLOW LINE Production: In Flow production either complex single parts (such as automotive engine blocks) or assembled products are made to "flow" through a sequence of operations by material handling devices (conveyors, moving belts, transfer devices, etc.). Examples of flow production include automated transfer machines for the production of complex discrete parts, and manual assembly lines for the assembly of complex products. These products require multiple operations at different machines; they can not be manufactured in one single machine.

CHARACTERISTICS Product Line Layout High volume production Machines are ordered in lines according to the operation sequence of one or more part types which are very similar to each other Dedicated/Special purpose machines and automated material handling equipment Throughput rates--high Work-in-process--low Long setup times but Setup/Run time ratio--low System is very inflexible Control is relatively simple

Production Line (FLOW LINE--- ASSEMBLY LINE) Layout

Production Line (FLOW LINE---ASSEMBLY LINE) Layout The product flows through an flow line while the personnel and equipment movements are limited Customer, Material, or Components WS 1 WS 2 WS 3 WS 4 Finished Goods Suitable for Repeated and Continuous Processes

IN PRODUCTION LINE LAYOUT MACHINES ARE LOCATED ACCORDING TO THE PROCESS PLAN (SEQUENCE OF PROCESSES)

The moving assembly line for cars is an example of the flow shop.

Robotic Assembly Line

Assembly workers on an engine assembly line inford Motor Company.