production

• Quality Control


  The monitoring, checking and testing of materials and components throughout the production process to ensure they conform to acceptable standards and tolerances specified within the Quality Assurance policies set out by the company
• Quality Assurance


  A series of planned actions and procedures are set up to check the product before, during and after manufacture
• Quality control inspection checks take place throughout the production process, and are performed in conjunction with strict guidance documentation produced by the company and the client
• What might be wrong with the raw materials?

  • Dimension
  • Defects
  • Warps, twists or bows in wood
  • Damage from transport or storage
• Typical quality control tests

  • Size tests for dimensional accuracy
  • Tests on electronic circuits
  • Tests to check parts have been welded together properly
  • Visual inspection to check quality of finish
  • Tests to check colour – matched against a sample
  • Tests to check strength of parts
  • Chemical analysis (e.g. moisture content or chemical composition)
• Many of these tests will be performed by the people manufacturing the items, although some are done by specialist QC checkers
• In most cases a sample of a product is tested, e.g. 10 out of every 1000 manufactured
• High Volume Production


  Continuous production of standardised items over a long period of time
• High Volume Production


  • Not employed by industries that undergo rapid changes in fashion or technology
  • Aim is to make as many products as possible in the most efficient manner possible and to make those products as consistent and identical as possible
• Measuring devices

  • Vernier callipers
  • Micrometer screw gauge
  • Co-ordinate Measuring Machines
  • GONOGO gauges
• High Volume Production


  • Aluminium cans
  • Plastic bottles
• Ford Model T


  Example of High Volume Production
• Economies of scale


  What makes it possible for products made in high volumes to have a lower unit cost
• Tolerance


  The minimum and maximum measurements specified, as every object cannot be guaranteed to meet the exact specifications when produced in large quantities
• Factors that allow lower unit cost in High Volume Production

  • Buying large quantities of parts and materials at lower cost
  • Lower wages - unskilled workers or robots/automated processes
  • Fast, efficient production
• Some products require great accuracy and may have tolerances of +/- 0.001mm
• High Volume Production


  • Requires large investment in capital for specific, purpose built equipment and automated systems
• Processes suitable for High Volume Production

  • Injection moulding
  • Blow moulding
  • High pressure die casting
  • Press forming operations
• Continuous flow


  Products made on a production line, one process after the other, usually highly or fully automated
• Repetitive flow


  Production broken down into sub-assemblies, which are assembled together at the end of the process
• GONOGO Gauges


  Used to check that specific parts are within tolerance
• Batch Production


  Many commercial products are made in batches, from just a very small number up to several thousand
• Batch Production


  • Often used by industries where change occurs fairly frequently, where the type of product remains similar but the exact nature changes regularly (e.g. seasonal products, fashionable products, hi-tech products)
• How to ensure consistency

  • Jigs
  • Formers
  • Templates
  • Moulds
• Batch Production


  • Equipment must be flexible enough to manage different versions of similar products, more general purpose than High Volume but still capable of consistent, accurate and quality manufacturing
• Batch Production


  • Processes are more labour intensive and require more skill than High Volume Production
• Processes used in Batch Production

  • Vacuum forming
  • Sand casting
  • Investment casting
  • Machining operations such as turning and milling, often CNC
  • Steam bending
  • Sewing
• Gantt Chart


  Provides a clear schedule to help to plan and track specific tasks against a time frame
• One-off Production


  Also known as bespoke or custom made, often referred to as job production in engineering
• One-off Products


  • Bespoke tailoring
  • Custom-made sports equipment or musical instruments
  • Bespoke furniture
• Critical Control Points (CCPs)

  Key stages of the project at which QC checks are performed
• One-off Production


  • Very expensive due to highly skilled craftspeople working carefully and methodically, and use of high quality, expensive materials
• Gantt Chart

  • Each activity is represented by a row
  • Coloured rectangles are used to represent the start and end of each activity
  • The right hand end of the table represents the planned end date
• Scrum


  A management tool originally used in software development, but has made its way to other industries
• One-off Production


  • Uses traditional, general purpose tools and equipment at a lower cost than High Volume Production
• Quality Assurance (QA)

  Putting into place all the actions which are required to ensure Quality, a responsibility of everyone that should be built into the process from day one
• Scrum


  1. The team divides tasks into short timescale 'sprints'

  2. The team attend daily 'Scum updates' where individuals feedback their progress towards the team goal

  3. The distribution of tasks can be updated based on these meetings
• Six Sigma


  A set of tools designed to minimise defects
• Six Sigma was introduced by Motorola in the 1980s
• Total Quality Management (TQM)


  A philosophy designed to ensure the products being manufactured are all consistent and of good quality, using the principles of 'continuous improvement' (kaizen) in every part of the manufacturing process