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					    Design & Technology
    Systems and production methods
    A system is a set of components arranged to carry out a
    particular function. All systems have inputs, processes and
    outputs; often they will have feedback as well.
    Systems for manufacturing graphics products require planning;
    system flowcharts are useful for this. They also need to be
    controlled, and these system controls can be visual, mechanical
    or electronic devices. Production systems also need to be
    checked for quality - a procedure called quality control.
    Graphics products manufacture can be either one-off, batch,
    mass-produced or continuous-flow, depending on the scale of
    production. Computer-aided manufacture (CAM) is widespread in
    all kinds of graphics production.
    Systems
    A system is a set of components arranged to carry out a particular
    function. Systems may include mechanical, electrical or electronic
    components. The block diagram below represents a system for
    producing a batch of leaflets.




    Input is what goes into the system - the raw materials. In a music
     system the input usually comes from a CD player or radio tuner.
    Process is the shaping and forming of the materials, or the
     exchange of information needed to effect the output. In a music
     system it is the amplifier that does the processing.
    Output is what comes out of the system - the finished product. In
     a music system, the speakers take care of the output.
System feedback
Most systems have a fourth element - feedback - which is simply a
way of changing the input or process as a result of what happens at
the output. In a music system, feedback is a human response to the
output from the speakers: if the music is too loud, or the radio tuned to
the wrong station, the user will reduce the volume or retune the radio.
In a system diagram feedback is shown like this:




An example of feedback in a production system is checking that the
product meets the specification, and adjusting the process to make
sure it does. Many systems have an automatic type of feedback,
where feedback from one part of the system switches another part of
the system on or off. This sort of system is called a closed system.
Planning systems
System flowcharts
When planning a production system you need to work out how the
different elements of the system fit together, with each part in the right
order. A flow chart is a good way of doing this. The one below shows
how to organise the production of a school newsletter.
 Manufacturing systems
 Any large-scale production system of the kind you would find in
 manufacturing is likely to include the following processes:
 Storage of raw materials, bought-in components, sub-assemblies
  and part finished products.
 Inspection of bought-in components to make sure they are of the
  required quality; Inspection of part-finished products to ensure
  they meet specifications; artwork. Inspection has to be done at all
  the crucial points in the production process.
 Operation is the processes of manufacturing.
 Movement of raw materials, part-finished products and complete
  products.




 Use these symbols when drawing a flowchart for large-scale
 production system
 System controls
 Systems need to be controlled if they are to continue functioning the
 way they were designed to do.
 Visual controls
 Controls can be simple visual aids for the designer. Two examples are
 registration [registration: correct aligning of colour blocks in a printed
 product ] marks and colour bars.
 Registration marks are used to make sure that colour printing lines
 up, because the various colours must line up with each other.
 Registration marks are usually shown in a cross shape. Sometimes
 work that is to be printed has colour-separated artwork, where the
 artwork for each colour is on a separate sheet.Colour bars are
 standard bars of colour with blocks of each colour printed. This is
 done to show the strength and evenness of the ink used and that the
 registration of the colours is correct.
 Mechanical / electronic controls
The table lists mechanical or electronic equipment used for control
and feedback in graphic production.

Equipment     Type of      Type of control               Example of feedback
              system

Rotary        Mechanical   Speed of movement of          Paper cut is ragged: blade
paper                      cutting blade; cutting        may need
trimmer                    fence can be set to           sharpening/replacing; cut
                           required distance, which      fewer sheets Wrong size:
                           allows repetition             reset fence

Computer      Electronic   Number of copies; paper       Number of copies wrong:
printer       or           type; quality of printout     reset on computer Quality
              mechanical   Repetition through repeat     of print poor: change paper
                           copies                        or ink cartridge

Photocopier   Electronic   Size of                       Size is wrong: reset size
              or           copy/enlarge/reduce;          Number of copies wrong:
              mechanical   number of copies made;        reset number required
                           type of paper or other        Quality of print poor:
                           materials; quality of         change paper or toner
                           printout; copy too            cartridge Contrast wrong:
                           dark/light                    adjust contrast control

CAM 2D        Electronic   Speed/depth of cut;           Cutting incorrect: adjust
card/vinyl    or           pressure on cutter; order     speed/depth and/or
cutter        mechanical   of cutting Repetition         pressure through software
                           though repeating process      or hardware controls Order
                                                         wrong: reset though
                                                         software controls

CNC 3D        Electronic   Speed/depth of cut;           Cutting incorrect: adjust
milling       or           rotational speed of cutter;   speed/depth, through
machine       mechanical   type/size of cutting tool;    software or hardware
                           order of cuttingRepetition    controlsOrder wrong: reset
                           though repeating process      though software controls

Quality control
Quality control is a specialised type of system control designed to
check that a product meets the design specification and is of the
prescribed quality. Before making a product, the designer should
decide what quality checks need to be done, and at what stage in the
making process they should be carried out.
A high-quality product will:
 meet the specification
 do what it is supposed to do
 be free of defects
 satisfy customer requirements
 Quality control checklist:
 check against the specification: does the product meet all aspects
  of the specification?
 is the text accurate, spelt correctly, with correct grammar and
  layout?
 have the correct shades of colours been used?
 are the registration marks correct and do they line up?
 have correct desktop publishing (DTP) layout templates been
  used?
 check measurements: are they within the tolerances specified?
 for products such as pop-up books, check the cut and fit of
  different parts: do they fit accurately and neatly without gaps?
 for products such as pop-up books and cards, check to see if the
  product works properly and as intended: do parts move as
  required?
    Production methods
 There are four main types of production system used in manufacturing
 graphic products, each one suitable for a different scale of production.
 One-off production is when only one of the product is made. It is
   labour-intensive, because every product is different. One-off
   graphic products might include a presentation book as a souvenir
   of a special event, or a model of a theatre set.
 Batch production is when a set quantity of the product is made.
   It may also use a lot of labour, but jigs and templates are used to
   aid production. Often the machines can be easily changed to
   produce a batch of a different product. Batch-produced graphic
   products include programmes for a play or concert, or posters to
   advertise a play or concert.
 Mass production is when a very large number of the product is
   made, usually on a production line - but the process cannot be
   continuous because the product regularly changes. Examples of
   mass-produced graphic products are newspapers and magazines.
 Continuous-flow production is when many thousands of products
   are made. The difference between this and mass production is
   that the production line is kept running 24 hours a day, seven
  days a week, to eliminate the expense of stopping and restarting
  the production process. The process is often automated and few
  workers are required. Continuous-flow production is used for
  graphics products which sell very large numbers throughout the
  year, and do not need to be frequently changed - such as cereal
  packaging.
 ICT in industry
 Information and communications technology is widely used in
 manufacturing graphics products. Its benefits are that:
 it makes it easy to produce accurate, complex, standardised
   drawings
 It allows complex shapes to be made with ease and precision
 it enables changes to be made quickly and easily, and
 it greatly simplifies batch or mass production

 Computer aided manufacturing (CAM)
 CAM machines are good for batch or mass production, and they are
 also useful for one-off products that are complicated to make. There
 are two types of CAM machine:
 2D CAM machines
 Plotter/cutters can be used either for cutting of card and vinyl, or (by
 replacing the blade with a pen) to produce drawings and lettering prior
 to cutting. Cutter/printers are more complex CAM machines which
 allow full-colour printing before cutting is done.
 3D CAM machines
 These are mainly used for cutting plastics, hard wax, soft metals and
 wood-based materials such as MDF. They are particularly useful for
 making prototype models and moulds for vacuum-forming. Some of
 these machines can have a scanner head fitted in place of the cutting
 tool, allowing 3D scanning to be done.
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