Design and Technologies Knowledge and Skills
This domain covers the technical knowledge that makes a design feasible. Candidates should understand materials and their properties - strength, durability, workability, conductivity, thermal behaviour - and how properties drive selection. Know the difference between properties (inherent behaviour of a material) and characteristics (how it performs in context). Understand basic manufacturing and construction processes (cutting, joining, forming, finishing), assembly and tolerance, and why tolerances matter for fit and function.
Systems thinking is central: inputs, processes, outputs, and feedback in mechanical, electrical/electronic, and control systems. Be able to identify a sensor (input), a controller (process), and an actuator (output) in a simple system description, and explain the role of feedback in maintaining a set condition.
Common traps: confusing strength with stiffness; assuming a heavier material is always stronger; ignoring safety factors; and forgetting that a technically workable design may fail on cost or manufacturability. Questions also test sustainability of materials - recyclability, embodied energy, renewability - so avoid treating any material as universally 'best'.
Worked example / rule of thumb: A shelf bracket must hold 20 kg with a safety factor of 2. Required design load = 40 kg. Select a section and material, then check deflection as well as stress - a bracket can be strong enough yet flex unacceptably. Rule of thumb: state the load, apply the safety factor, then check both strength and stiffness against the function. Always justify a material choice by naming the property that matters for that function.