Question 15
Controlling access to premises is an issue that affects many small businesses. Loss or damage to property from unauthorised access can be very expensive and result in loss of business if premises have to close while damage is repaired. Small businesses need to consider how to make it easy for authorised persons to access their premises while deterring, detecting and protecting from unauthorised access and informing police and business owners.
Identify a machine or mechanism solution to help businesses control authorised and unauthorised access to their premises. Explain how engineers have used their expertise in materials science, mechanics and control technology to develop this solution. Include two benefits of the solution for a small business in your response.
Each domain of expertise adds one working part to the lock, and each part is one mark
Watch a multipoint lock get built one domain at a time, then watch what it does for the business. The tally on the right fills one box per sentence.
Every domain sentence names a part and says what it does. The two benefits happen to the business, and they are different from each other.
Build the answer one sentence at a time and watch the marks
Tap a sentence to add it to your answer, and tap it again to take it out. The marking guide ticks each dot point your answer earns. The 2026 syllabus allows up to 150 words per question, so the counter keeps you honest.
Nothing written yet. Start with the solution.
Work through the solution one mark at a time
Write your own sentence for each step before you reveal it. The quoted wording is QCAA’s sample response.
Name one specific mechanism. QCAA’s sample names multipoint locks inside its first sentence:
“…engineers have used their expertise in mechanics to develop multipoint locks that provide multiple locking points around doors or window frames…”
Any sensible device earns this mark, as long as the rest of your answer is about it. The guide’s Notes list these:
Valid machine/mechanism solutions may include: boom gates, bollards, security systems (e.g. lights, alarms, cameras), or other suitable response consistent with a reasonable understanding.
Marker: identifies a valid machine/mechanism solution
Give a property of the material and what that property achieves for the lock.
“Their expertise in materials science ensures that the locking mechanisms are made of strong and durable materials resistant to damage or tampering.”
Expertise in materials science may include: strength-to-weight ratio, impact resistance, weather resistance, or other suitable response consistent with a reasonable understanding.
Marker: explains how the engineers have used their expertise in materials science
Describe the moving parts and what their motion does. The sample puts this in the same sentence as the solution:
“…provide multiple locking points around doors or window frames by moving multiple metal components from one central point in the lock.”
Expertise in mechanics may include: movable barriers, moveable bollards, moveable cameras, or other suitable response consistent with a reasonable understanding.
Marker: explains how the engineers have used their expertise in mechanics
Name the control components and say what they decide. Here they decide who is authorised.
“To allow authorised persons to operate the locking mechanisms and prevent unauthorised access, engineers have used their expertise in control technology, e.g. logic gate circuits that have input devices such as swipe cards, keypads or biometrics.”
Expertise in control technologies may include: remote controls, including smartphones, wi-fi, or other suitable response consistent with a reasonable understanding.
Marker: explains how the engineers have used their expertise in control technology
A benefit is something that happens to the business. The sample goes straight to money.
“Having more secure and durable locks on windows and doors will reduce the potential costs for small business owners that result from theft or vandalism caused by intruders.”
Benefits to small businesses may include: reduced insurance premiums, deters intruders, alerts police/business owner to break in, easily changes who has authorised access, or other suitable response consistent with a reasonable understanding.
Marker: includes one benefit to small businesses
The second benefit has to be a different kind of benefit. Cheaper repairs would only restate lower theft and vandalism costs.
“Additionally, the use of controlled entry of authorised persons could provide the business with a record of who has been on the premises and when.”
To prevent unlawful access to property, engineers have used their expertise in mechanics to develop multipoint locks that provide multiple locking points around doors or window frames by moving multiple metal components from one central point in the lock.
Their expertise in materials science ensures that the locking mechanisms are made of strong and durable materials resistant to damage or tampering.
To allow authorised persons to operate the locking mechanisms and prevent unauthorised access, engineers have used their expertise in control technology, e.g. logic gate circuits that have input devices such as swipe cards, keypads or biometrics.
Having more secure and durable locks on windows and doors will reduce the potential costs for small business owners that result from theft or vandalism caused by intruders. Additionally, the use of controlled entry of authorised persons could provide the business with a record of who has been on the premises and when.
The sample sits exactly on the 2026 limit of 150 words. The six-sentence answer in the builder above earns the same 6 marks in fewer words.
Marker: includes a second benefit to small businesses
Each phrase of the question gave you something
The 2025 subject report says effective responses named a valid machine or mechanism, then explained the materials science, mechanics and control technology behind it and gave two benefits to the business. It chose its sample excerpts to show a clear and concise explanation.
You have to choose the machine yourself and then connect three separate bodies of knowledge to it in a scenario you have never seen. QCAA did not publish a band for this question. It reads as complex unfamiliar because the 2024 subject report placed the same synthesis task, set in a different scenario, among the complex unfamiliar questions.
If I had to guess where you might lose marks, it would be the benefits. Three good sentences about the lock and no benefit is a routine 4 out of 6, and a second benefit that repeats the first earns nothing. The other leak is a domain sentence such as “engineers used materials science” that names the domain and never says what it did. In 2026 the whole answer has to fit in 150 words, which six plain sentences do easily.
Only mark this done when you could do it without help. Reading the solution does not count.
Question wording, any figures and marking-guide steps are from the 2025 QCAA Engineering external assessment, © State of Queensland (QCAA) 2025, licensed under CC BY 4.0, and have been adapted, except where a third-party source is named. Tangent Tuition is not affiliated with the QCAA.
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