A configurator the factory cannot honour
The most expensive failure in this category, because it happens after payment. Every constraint the workshop applies in its head needs to become a rule: maximum spans, weight limits per fitting, finishes unavailable on certain substrates, minimum sizes, combinations that void a supplier warranty. Get the production lead to try to break the configurator before it goes live, and treat every impossible order that gets through afterwards as a rule that needs writing rather than a one off.
Pricing logic in two places
The website has a formula, the office spreadsheet has a slightly different one, and both are edited by different people. Six months later nobody can say which is right, and margin analysis becomes guesswork. Hold the calculation once, call it from everywhere, version it, and store the inputs and the resulting price with every order so a historical quote can be reproduced exactly. If a rule has to change mid season, effective dating keeps existing quotes honourable.
Lead times that ignore the calendar
Australian production calendars have quirks that generic systems miss: public holidays that differ by state, the summer shutdown that closes suppliers as well as your own workshop, and imported material lead times that stretch around Lunar New Year. A promise engine that does not know about these will confidently commit to dates in the middle of a fortnight when nobody is at the bench. Load the calendar properly, review it annually, and make shutdown dates a scheduled task rather than something remembered in December.
No stored version of what was ordered
If the specification exists only as rendered text on an invoice, you cannot reproduce it, cannot analyse which options actually sell, and cannot defend a warranty claim. Store the structured configuration alongside the human readable summary, keep the version of the rules that priced it, and make both retrievable from the order. This costs almost nothing at build time and is very difficult to add retrospectively.
Consumer law treated as a returns policy
Custom made goods cannot generally be returned for change of mind, and it is reasonable to say so clearly. What does not change is that consumer guarantees under Australian Consumer Law still apply: the goods must be of acceptable quality, fit for the purpose you were told about, and match the description or sample. A deposit that is genuinely part payment is treated differently from a security deposit for GST purposes, so agree the treatment with your accountant and build the system to match rather than deciding it invoice by invoice.
Building a full quoting platform when you needed a form
Not every made to order business needs configure, price and quote software. If you sell a handful of configurable products with a few options each, a well built form on the site, a pricing service and a clean handoff into your existing job system will do the work at a fraction of the cost and complexity. The case for something heavier appears when option counts run into the hundreds, when dealers and reps quote on your behalf, or when a single job carries dozens of configured line items. We will tell you which side of that line you are on.