Modern Scales of Production - Detailed Notes

Modern Scales of Production

  • This unit covers different scales of production, the use of computer systems, efficient material use, and various production systems.
  • Learning outcomes include understanding one-off, batch, mass/line, and continuous production; computer systems in production, distribution, and storage; efficient material use; Unit Production Systems (UPS); modular/cell production with robotics; Flexible Manufacturing Systems (FMS); and Quick Response Manufacturing (QRM).

Introduction

  • Designers and manufacturers must consider the scale of production as it influences design and manufacturing decisions.
  • Using ICT in manufacturing can be costly and time-consuming, so different production scales should be considered.
  • Investing in CAD/CAM equipment may not be feasible for smaller-scale production.
  • Manufacturing efficiency is often improved by incorporating sub-assemblies and bought-in components.

Scales of Production

  • One-off/Bespoke Production:
    • Products designed and manufactured for a single, specific situation.
    • Examples: iron gates, jewelry, furniture, or hi-tech items like a carbon fiber bicycle frame for an Olympic athlete.
    • Items are unique and command a higher price than mass-produced items.
    • Individuality and uniqueness are often desired by the customer.
  • Batch Production:
    • A set number of items are produced in a single run.
    • The batch size can vary from a few (small batch) to a few thousand (large batch), but there's a limit.
    • Jigs and templates help ensure similarity among items.
    • Rapid prototyping like laser cutting and 3D printing may be used if machinery is available.
  • Jig Definition:
    • A device used to hold material and guide cutting tools.
    • Ensures repeatable accuracy and high quality.
    • Example: A carpenter using a jig to make a hole with specific alignment and depth.
  • Template Definition:
    • A tool used to repeatedly mark out shapes.
    • Example: Using a template to draw around 100 acrylic keyrings to ensure they are all the same shape.
  • Mass/Line Production:
    • Items made in large amounts, often in very high volumes.
    • Aims to meet the demand of every consumer who wants the item.
    • Examples: light bulbs, nuts and bolts, and cars.
    • Producing beyond customer demand can lead to large stockpiles and storage issues.
    • Many expensive consumer items are produced to order but considered mass-produced due to high volumes.
    • Materials may be adapted for economic reasons, and more advanced machinery may be necessary.
  • Continuous Production:
    • Production runs 24/7 because there is a constant need for the product.
    • Stopping production would cause issues for consumers or industry.
    • Examples: milk, water, electricity, newspapers, bread, and oil.
    • Material and machinery costs need to be carefully considered.
  • Unit Production Systems (UPS):
    • Used in textile manufacturing.
    • Employs an overhead transporter system with hanging carriers to move components between workstations.
    • Reduces handling operations and optimizes manual labor while improving quality.
  • Vertical In-House Production (Vertical Integration):
    • A company owns its supply chain.
    • Outsourcing occurs when a company requires external parts.
    • Advantages:
      • Reduced risk of price increases for components.
      • Less susceptibility to suppliers going out of business.
      • Protection of brand and IP rights.
      • Easier implementation of Quality Assurance strategies.
    • Example: Apple uses vertical integration for casings, CPUs and proprietary PCBs but still outsources RAM, screens (Samsung), and Wi-fi/Bluetooth (Qualcomm).

Efficient Use of Materials

  • Material Cost, Form, Manufacturing Processes, and Scale of Production:
    • Material choice is often dictated by the part's specification.
      • Example: A twist drill must be made from high-speed steel.
      • A hinged lid for a freezer container would be made from PP.
    • Cheaper versions might compromise product quality.
    • The amount of material used is a key consideration.
    • Advances in FEA and CAD can improve products while using less material.
  • Just in Time (JIT):
    • A system to ensure customers get products when they need them without stockpiling.
    • Requires the manufacturer to ensure timely arrival of parts from suppliers.
    • Example: Land Rover may only have enough parts to make cars for one day, relying on the production pipeline for timely delivery.
  • Design and Economic Use of Materials:
    • Includes designing nested parts to minimize waste during laser cutting.
    • Ordering large sheets of wood that can be economically cut for one-off furniture jobs.
  • Material Properties, Processes, and Scale:
    • Materials and processes used depend on material properties, available manufacturing processes, the scale of production, and the intended cost.
    • Rotational molding is used for children's toys to create hollow, thick-walled, strong, and lightweight products.
    • Rotational molding is cost-effective for large scale production, but the initial cost of machinery and molds must be considered.
    • Injection molding would require multiple molds and gluing parts together, increasing costs and potentially weakening the product.
  • Manufacturing Processes for Accuracy and Waste Reduction:
    • Products need to be accurate and uniform.
    • Automated machinery is used to ensure accuracy, reduce costs, and save time.
  • Comparing Bulk and One-Off Production:
    • One-off production involves bespoke design and manufacture of single products, requiring manual labor and skill.
    • Bulk production uses automated manufacturing techniques.
    • Artisans cannot justify the investment in automated machinery for one-off items.
    • Customization of mass-produced items (e.g., footwear and clothing) is not truly bespoke.
  • Bulk Production and Cost:
    • Bulk production does not always equate to cheaper products.
    • Example: Herman Miller's Aeron office chair is expensive due to ergonomic features and hand-assembled quality components.
    • Contrast: Robin Day’s PP Chair is cheaper and a best-selling chair of all time.
      *Please attempt the past paper for next lesson and we will go through the answers together to see where you may have made a mistake or where you can improve your answers. Please write in your homework planner: Complete Q5 from AQA SAMP1 Summer 2018 Next lesson: Production systems

The Use of Computer Systems

  • Computer Systems for Planning and Control:
    • Computers have revolutionized product manufacturing.
    • Sophisticated software uses mathematical calculations for planning and organizing complex manufacturing facilities.
    • Barcodes and Radio Frequency Identification (RFID) tags facilitate information transfer relating to components and stock.
  • Computer Systems for Manufacturing and Production:
    • Modular/cell production combines CNC machines in a group (CNC module or cell).
    • Robotic arms often load material at the start of the process.
  • Robotics - Generations:
    • 1st generation: responds to a pre-set program, obsolete.
    • 2nd generation: fitted with sensors which feedback information, often using a digital camera.
    • 3rd generation: uses sophisticated sensors and AI, detects changes in the environment and modifies its working program.
  • Robotics - Types:
    • Beam Transfer: Simple robots on parallel slides or beams used to pick up components (e.g., in the car industry).
    • Arm robots: Versatile, mimicking the human arm; movement directions are 'degrees of freedom'; the 'hand' is the effector.
    • Automatic Guided Vehicles (AGV): Driverless forklifts using sensors and reflectors to carry items, often used with JIT systems.
  • Programming Methods:
    • Teach Pendant: Guiding the robot through moves using a remote control-like device.
    • Walkthrough: Physically taking robot through the process, recording movements.
    • Off line: Using Virtual Reality simulations to program and test the robot without risk of damage; used for rehearsing dangerous operations.
  • Benefits of using Robots:
    • Carry out mundane, repetitive tasks.
    • Perform physically demanding tasks.
    • Work in hazardous areas (e.g., bomb disposal, deep sea exploration).
    • Maintain high levels of accuracy, consistently and quickly.
    • Work for long periods without breaks, reducing human error (though programming errors are possible).
  • Drawbacks of using Robots:
    • Poor mobility and flexibility compared to humans.
    • Limited degrees of freedom.
    • High setup and maintenance costs.
    • Employment issues due to human worker replacement.
  • Quick Response Manufacturing (QRM):
    • Consumer needs rapidly change, so manufacturers prefer making to order.
    • Example: Jaguar and Land Rover make cars that are already sold which reduces unsold stock.
    • QRM reduces waiting time.
  • Manufacturing Processes Flexibility:
    • Mass production of items like aerosols uses dedicated equipment due to high demand.
    • Other markets may require more flexible equipment for batch production.
  • Flexible Manufacturing Systems (FMS):
    • Machines organized into cells with a temporary store for partially completed work.
    • A host computer sequences jobs and monitors machine performance.
    • Different products can be made in the same cell simultaneously.
  • Examples of Flexible Equipment:
    • Press Formers: Interchangeable dies; can be expensive.
    • CNC Punches: Programmed to punch various designs.
    • CNC Laser Cutters: Programmed to cut various shapes in different materials.
    • CNC Lathes and Milling Machines: Programmed for accurate jobs or batches.
      • Lathes turn diameters of bars, machine threads, and face and drill ends.
    • Robot Arms: Programmed for welding, spraying, lifting, etc.
  • Computer Systems for Production, Distribution, and Storage:
    • Stock (inventory) monitored using barcodes or RFID tags.
    • JIT systems rely on these for efficient flow of parts.
    • Storage, distribution, and sales monitored by computer systems (EPOS systems).
    • Computer Integrated Manufacture (CIM) brings design elements together under computer control; organizes scheduling and materials ordering.
  • Standardized Components:
    • Fit other elements of a design.
    • British Standard Whitworth screw thread (1841) was a major breakthrough.
    • ISO metric standards ensure consistency.
    • USA and Canada use an inch-based thread sizing system, ,but ISO metric threads are becoming standard.
  • Bought-In Components:
    • Used when in-house manufacturing is impractical or uneconomical (e.g., CPUs and RAM).
    • High-end manufacturers buy from companies like Samsung, Intel, and AMD.
    • Apple and Samsung make their own CPUs but still buy some parts.
    • Car, bike, and furniture manufacturers buy fittings and accessories from 3rd-party suppliers.
  • Changing Standards:
    • Can cause major problems.
    • Smartphones use various connectors for charging.
    • A 2019 ruling mandates USB-C connections.
    • Companies like Apple with proprietary Thunderbolt/Lightning connectors will face challenges.
    • Consumers may find existing accessories obsolete.
  • Sub-Assemblies:
    • Elements of a product created as a unit before final assembly.
    • Example: A bicycle with sub-assemblies like gear cassette, braking system, lighting system, wheels, saddle, frame, and chain.
    • Manufacturers concentrate on making their parts well, using sub-assemblies from other manufacturers.

Prep

*Please attempt the past paper for next lesson and we will go through the answers together to see where you may have made a mistake or where you can improve your answers. Please write in your homework planner: Complete Q16 from AQA SAMP1 2018 Next lesson: Digital design and manufacture
Complete Q16 from AQA SAMP1 2018 Next lesson: Digital design and manufacture

Summary

  • Scales of production range from one-off/bespoke to continuous production, with different materials and processes depending on costs.
  • Modern manufacturing relies on new materials and production techniques using technologies like Virtual Reality, laser cutting, and 3D printing.
  • Production lines need to be flexible to adapt to changing needs.
  • Expensive robotic production lines are not practical for one-off production.
  • Manufacturing products can be improved by the use of computer-aided engineering.

Revision Notes

  • Familiarize yourself with acronyms like UPS, QRM, FMS, etc.
  • Consider how a 'one-off' prototype could be mass produced.
  • Know how computer systems are used in planning, monitoring, and production.
  • Understand how products can be made quickly and accurately in larger numbers (batch and mass production).
  • Consider how to reduce wastage and increase production time.