MANUFACTURING (Lecture 4)

2 Cycle of Manufacturing  Manufacturing spans a large sequence of interrelated phases  It involves research, development, design, production, quality control, selling and servicing of a product  Research & Development –Research is an activity that looks at brand new ideas –Development uses research to create new products –Market research – the current and recent trends in the market –Look for a suitable material –Recommend some choices of material to be chosen –Keep on looking for the methods that could improve the comfort level, productivity of the current products –Productivity is the ratio of the overall outputs to the inputs of a company

3 Cycle of Manufacturing  Design –Decide the material, the size, color, and the shape etc. –Assembly of a part in the forthcoming product is important in design –Prototype – a handmade test model of the product –Plans for the steps of manufacturing the new product – computer-aided design (CAD) –The plans are later used by the production department  Production –Production department is responsible for actually making the company’s product –Schedule is a timed plan of activities –Purchasing department has to procure the required type of raw material or parts –The suppliers have to deliver the material according to production schedule

4 Cycle of Manufacturing  Quality Control –Quality control – making sure that the products are all alike or uniform and according to the standards defined by the customer –A standard is a system used for comparison – helps your customers see the quality and performance easily –The process starts from incoming quality control – inspecting the raw materials –Inspections are carried out at the end of assembly lines of different parts –The final step is the inspection of the end-product –Many companies check the quality control used by their suppliers –A supplier gets their new products (prototypes) approved by the representative engineers of their customers before going onto large scale production –After passing the test and being approved, a supplier receives a Supplier Certification Award –Several groups – American National Standards Institute (ANSI), American Society for Testing and Materials (ASTM), Society of Automobile Engineers (SAE) –Measurement systems – MKS System (meters and centimeters), FPS System (feet and inches)

5 Cycle of Manufacturing  Safety –Safety means freedom from injury or any danger of injury –Colorful and eye-catching signs are posted in a factory –Occupational Safety and Health Administration (OSHA) establish safety rules –National Institute of Occupational Safety and Health (NIOSH) approve protection equipment such as hard hats and safety glasses –Environmental Protection Agency (EPA) restricts hazardous materials thrown into air or water, mostly from chemical plants  Sales & Marketing –Marketing – finding buyers for a company’s product –A company may sell its products to wholesalers or dealers –Wholesaler – a company that purchases large amounts from a manufacturer and then sells smaller amounts to retailers –Retailer – a company, or store, that sells products to consumers, e.g. Panda, Wal-Mart

6 Cycle of Manufacturing  Servicing –After-sale-services – products that need maintenance or that have been broken –Warranty – terms under which a company repairs or replaces a defective product –The product becomes either a throwaway or a repairable product after the warranty period –The company has its own repair shop or some dealers are responsible for this task

7 Manufacturing Approaches  Craftspeople, for centuries, make things on their own – carpenters, shoemakers and glassblowers etc  People used to run their own trade at their homes with a small setup  This methodology of manufacturing is known as crafts approach  Custom-made items are often made through crafts approach, e.g. an exotic sports car or products for handicapped people.  Factory system came into being during industrial revolution – people working under one roof  Activities of workers could be tightly supervised (tasks assigned, output accurately measured and time attendance checked etc)  Factory system has advanced a lot since its birth  Factory system gave way to mass production and assembly line production  Assembly line – each worker does one step and passes the item on for the next step  Assembly line products are standardized and interchangeable

8 Manufacturing Approaches Craft ProductionMass Production Workers are skilled Workers make a product from start to end Work is varied and interesting No two parts are exactly alike Only one item is produced at a time The work could stop anytime Each item takes long time Cost of each item is very high Quality depends mainly on the skills of the craftsman Workers need limited skill Workers work for only one step or stage Work is routine and boring Parts are interchangeable One production run produces many items All the operations are synchronized Time of production per part is reduced Cost of each item is very low Quality depends on the accuracy of the machines and how well the stages are arranged

9 Manufacturing Approaches  Factory system brought many changes to the society: –standard of living of the people living in industrialized nations improved –unions were formed to protect the rights of workers –child labor laws were passed –the number and importance of schools and day-care-centers increased

10 Contemporary Trends  Automation is the process of controlling machines through computers  A set of instructions called a program – program control  Sensors provide feedback to make modifications in these programs – feedback control  A sensor is a device that gathers information about its environment  Automation has introduced concepts like robotics, CNC, CAD, CAM and CIM.  Robotics – technology that deals with the use of industrial robots  An industrial robot has one mechanical arm and is controlled by a computer  Robots do jobs that are hazardous, boring, or unpleasant for people  They can be easily reprogrammed to do other tasks  Uses of robotics – spray painting, welding and pick-and-place jobs etc.  CNC – computerized numerical control – machine tools operating through commands from a computer

11 Contemporary Trends  CAD – computer aided design – designing and planning activities related to a part  CAM – computer-aided manufacturing – programming computers to operate all the machinery  CIM – computer-integrated manufacturing – all the computers in the company are linked together, or integrated  Uses of CIM –design and production departments can communicate instantly –purchasing department can tell their suppliers when to deliver production materials –marketing department can plan when to start selling products –management can direct the entire company from one location.  Other trends in the modern industry – JIT and Flexible Manufacturing  JIT – no storage cost, the raw material arrive at the factory only when it is required  Flexible Manufacturing – using the same set of machines and assembly lines for different models – small batches

12 Contemporary Trends Cutting a T-shaped profile from a block of steel, using a CNC wire-cut machine

13 Planning & Control  Modern manufacturing industry consists of fabrication and assembly  A plant has to –purchase raw material or parts –convert them into specific components –assemble the components into the several products  Different products could contain several common components Fabrication Assembly Storage Plant Raw Material or Parts Finished Products Storage A Typical Manufacturing Plant

14 Planning & Control  The information-subsystems that play a vital role in the smooth running of the company are –Demand forecasting –Operations planning –Inventory planning and control –Operations scheduling –Dispatching  Demand Forecasting –history and the current trends –sales data reflects its effectiveness  Operations Planning –development engineers look for a better manufacturing sequence –the input comes from standard operation times, setup times –machines and other facilities are grouped for a proper assembly-line operation

15 Planning & Control  Inventory Planning & Control –includes parts, raw materials, assemblies, supplies etc. –depicts the order quantities; reorder points, safety stocks of raw materials, and manufacturing batch sizes  Operations Scheduling –a detailed operation sequence for individual activities –start and stop times for all operations –schedule conflicts on production facilities are resolved here  Dispatching –responsible for initializing production –releases work orders to production operations at the appropriate time

16 Operations Scheduling  It is the heart of entire planning and control systems  Compromises must be made between economic batch sizes, due dates, resource constraints, manpower leveling, and facility utilization  Program evaluation review technique (PERT) charts are used for scheduling activities. It is a powerful tool  PERT chart tell a manager –list of operations necessary to finish a project –time needed for each operation –critical activities – activities that consume the largest part of project-completion-time  Critical path – a sequence of critical activities  Using PERT chart is also named as critical path method (CPM)

17 Operations Scheduling  Critical Path Method (CPM) Activities in a Manufacturing System ActivityDescriptionRequired PredecessorDuration AProduct designNone6 BMarket researchNone2 CProduction analysisA3 DProduct modelA5 ESales brochureA3 FCost analysisC4 GProduct testingD5 HSales trainingB, E3 IPricingH2 JProject reportF, G, I A, 6 B, 2 C, 3 D, 5 H, 3 F, 4 G, 5 I, 2 J, 1 E, Network Diagram for CPM A→D→G = 16 Critical A→C→F = 13 A→E→H→I = 14 B*→H→I 3*+3+2 = 8 Critical Path Analysis