NCEA Level 2 Technology cheat sheet

Brief development sequence: identify the issue and context, gather stakeholder and resource information, write a conceptual statement of purpose, then write specifications that state measurable fitness-for-purpose criteria; revise both as evidence emerges.

A usable specification is testable: state a value, a unit and a test method (for example, "supports a 15 kg static load for 60 s without permanent deformation, tested on a flat rig").

Feasibility check before committing to a design: technical (skills, materials, processes), economic (cost against budget), time (schedule), and legal or ethical acceptability; a design failing any check is modified or rejected.

Planning documents and their roles: task list for scope, Gantt chart for duration and overlap, milestone and review points for decision gates, resource schedule for materials, tools and people.

Critical path method: the critical path is the longest chain of dependent tasks; it fixes the minimum project duration, and any delay on it delays the whole project.

Prototype types are chosen by purpose: proof-of-concept tests the key idea, mock-up tests form and fit, functional prototype tests technical performance; each must state what is being tested and the pass/fail criteria.

Testing versus trialling: testing measures defined properties under controlled conditions against criteria; trialling places the prototype with real users in the intended context to reveal usability and durability issues.

Evaluation judges the outcome against each specification separately, cites evidence from tests and trials, and records modifications with the justification for each change.

Stakeholder analysis: identify the end user, client, manufacturer and wider community, record what each needs, and document how their feedback altered the brief or specifications.

Systems model: input, process, output, with feedback and control; the system boundary defines what is inside the system and what is treated as environment.

Open loop control takes no output measurement and cannot correct error; closed loop control senses the output and adjusts the input to hold performance near a set point.

Redundancy is duplicated components or pathways so a single failure does not remove function: active redundancy detects and switches automatically, passive redundancy sits in standby.

Reliability is the probability that an item performs its required function for a stated time under stated conditions; it improves with simplicity, derating of components and defined test and maintenance regimes.

Common failure modes are wear, fatigue, corrosion, overload, thermal stress and human error; FMEA ranks them by severity x occurrence x detectability to set priorities.

Material selection criteria: strength and stiffness, hardness, toughness, density (strength-to-weight), thermal and electrical conductivity, corrosion resistance, workability, cost and recyclability.

Mechanical advantage MA = output force / input force; velocity ratio VR = distance moved by effort / distance moved by load; efficiency = (work output / work input) x 100%, so MA/VR gives efficiency for a machine.

Electrical relationships: V = IR (Ohm's law), P = VI; in series resistances add and current is shared, in parallel voltage is shared and branch currents add.

Whole-of-life thinking in selection: material sourcing, energy used in manufacture and in use, maintenance, and end-of-life disposal or recycling are assessed alongside performance and cost.

Technology is purposeful intervention: it designs or makes something to meet a need or realise an opportunity, and it is not simply science applied.

Every technological outcome has a functional nature (what it does) and a physical nature (what it is made of and how it is put together); the two must be matched to the intended purpose.

Fitness for purpose is judged against specifications in the intended context of use; an outcome used in a different context, or by different users, may no longer be fit for purpose.

Outcomes take the form of products, systems or environments, and each form is evaluated with different criteria and evidence.

Technology both shapes and is shaped by society: cultural values, ethics, legislation, economics and environmental concerns influence design, and the resulting outcome changes behaviour and practice.

Invention is the creation of a new concept or device; innovation is its first successful implementation and use in a market or context, so innovation need not involve a new invention.

Technological knowledge includes know-how and tacit knowledge validated through successful practice, not only theoretical knowledge validated by experiment.

Technological outcomes can produce unintended consequences, positive or negative, which are weighed as part of design decisions and later evaluation.

Appropriateness is context-dependent: the same technology may be suitable in one cultural, environmental or economic setting and unsuitable in another.