Resistant Materials
Systems & Control
These icons indicate that teacher’s notes or useful web addresses are available in the Notes Page.
This icon indicates that the slide contains activities created in Flash. These activities are not editable.
For more detailed instructions, see the Getting Started presentation.
1 of 23
© Boardworks Ltd 2005
Learning objectives
Learning objectives
To understand what a system is.
To portray a system in a systems diagram.
To split a system into its three main parts: input,
process and output.
To recognize sub-systems which may be part of any
of these three areas.
To apply systems to structures, transport and
machines.
To draw flowcharts correctly, including any feedback.
2 of 23
© Boardworks Ltd 2005
Systems and control
A system is a series of:
components,
operations
or activities.
When they are joined together, a task can be carried out.
Control is used to manage a system.
How does each image above represent a system?
What is the control in each situation?
3 of 23
© Boardworks Ltd 2005
Working systems and control
An organized working environment does not just happen; it
has to be planned. You need a system for organizing it. You
need to control the working environment to make sure that it
runs smoothly and safely.
Which systems would you put in place to make this
classroom safer, and what would the controls be?
4 of 23
© Boardworks Ltd 2005
A system for issuing materials
In a school workshop, you could have a system for issuing
materials.
The basic features of the system, or stages in the process,
might be:
1. Fill in a form
2. Form dealt with by teacher
3. Collect the materials
This can be drawn as a simple systems diagram.
Fill in form
5 of 23
Form
processed
by teacher
Collect
materials
© Boardworks Ltd 2005
Systems
Systems have three main parts:
Input
Process
Output
In this example:
The input is the
information on
the form
6 of 23
It is
processed by
the teacher
The output is
the finished
material
© Boardworks Ltd 2005
A sub-system
Stages in the basic process:
Input
Process
Output
Form
Processed
by teacher
Materials
A lot needs to happen
between the process and
output stages.
This forms a subsystem of the main
system diagram.
7 of 23
The teacher needs to
pass all forms to a
technician who measures,
cuts and stacks materials
to return to the teacher to
hand out.
© Boardworks Ltd 2005
A simple systems diagram
8 of 23
© Boardworks Ltd 2005
Structural systems
A structural system is a series of constructional components.
When they are joined together, the task of constructing a
structure can be completed.
Examples of structural systems are:
Bridges
Buildings
Roads
Railways
9 of 23
© Boardworks Ltd 2005
Transport systems
Transport systems
A road system is a collection of roads, motorways
and dual carriageways.
These roads are component parts.
The parts are joined together to build a complete
system.
The road system fulfils the task of moving people
around the country.
There is a rail system and an underground
system.
Each of these systems is a sub-system of the
overall transport system for the country.
10 of 23
© Boardworks Ltd 2005
The London Underground transport system
Which systems and sub-systems are evident here?
11 of 23
© Boardworks Ltd 2005
Mechanical systems components
12 of 23
© Boardworks Ltd 2005
Gears
13 of 23
© Boardworks Ltd 2005
Levers
14 of 23
© Boardworks Ltd 2005
Pulleys
15 of 23
© Boardworks Ltd 2005
Mixed mechanisms
16 of 23
© Boardworks Ltd 2005
Flow charts
Flow charts are used to explain the processes involved in
systems.
A flow chart will explain:
The
activities
that
happen
17 of 23
The order
in which
they
happen
Any
decisions
Any
feedback
or
changes
necessary
© Boardworks Ltd 2005
Flow chart symbols
18 of 23
© Boardworks Ltd 2005
Flowcharts
Here are
two
examples
of simple
flowcharts:
19 of 23
Start
Start
Do something
Sand wood
Stop
Stop
© Boardworks Ltd 2005
Feedback
There are not many processes where you can just start, do
something and stop.
Usually some decisions have to be made.
Is it smooth enough?
Is the length right?
Do you need to cut more?
Feedback is used to control whether a process continues,
changes, repeats or ends.
20 of 23
© Boardworks Ltd 2005
Feedback
21 of 23
© Boardworks Ltd 2005
Feedback
Simple process:
Start
Process with
feedback:
Start
Sand wood
Sand wood
Stop
Now draw your own flowchart,
including any feedback, showing
the processes involved in
making a model bridge.
22 of 23
Smooth
enough?
No
Yes
Stop
© Boardworks Ltd 2005
Key points
Key points
A system can be represented in a systems diagram.
A system has three main parts: input, process and
output.
A sub-system can exist in any of these parts.
There are systems evident in structures, transport
and machinery.
Flowcharts explain the processes involved in systems
and are drawn using special symbols.
Feedback is also represented in flowcharts with a
‘decision’ box with ‘yes’ and ‘no’ options.
23 of 23
© Boardworks Ltd 2005