A quotation system that draws its own engineering

The problem

The client builds configurable smart-locker installations, and no two are the same: banks, columns and door patterns change with the site, and so does the price. Every quotation was assembled by hand in a large Excel workbook, and every quotation needed a presentation drawing that only the design team could produce.

The friction

The costing workbook worked, but only one person fully trusted it. The configuration rules — door sizes, technical compartments, control-panel placement, stands, castors, authentication hardware — lived in a few people's heads rather than anywhere a system could read them. Margin approval happened informally. And because the quotation went out as both a PDF and a spreadsheet, the two formats drifted apart.

The system

A web application that takes the enquiry, configures the locker bank — including the unequal door and column patterns real sites need — and reproduces the company's own costing to the rupee.

That last point mattered more than any feature. Before the system did anything new, it had to produce the same number the workbook produced. A regression test pins the costing engine against a real historical quotation, so no later change can move money quietly.

On top of that sits the approval logic and the document generation: quotations come out as a customer PDF and a formatted Excel, from one source, so they cannot disagree.

The drawing is the second half. When the salesperson asks for one, the application writes the configuration to a job queue. A watcher on the company's own engineering workstation picks it up, drives SolidWorks unattended to build the locker geometry and a dimensioned multi-view presentation drawing, exports the PDF, and attaches it back to the quotation — appended into the customer PDF, embedded in the Excel, bundled into the download. A browser-based 3D view of the configured locker, matched to the company's own rendering style, comes from the same pipeline.

The workflow

Sales enters the enquiry. The system handles the configuration arithmetic, the costing, the documents and the drawing. Quotations that fall below the margin floor are held for named approval before they can go out.

A person decides the price. The system does everything repetitive around that decision.

What we learned

Reproduce the spreadsheet before you replace it. The first milestone was not a feature — it was the system returning the same number the workbook did, on a real past quotation, every time the code changes. Trust in the arithmetic had to come before anything was added to it.

The split is the same one we look for in every engagement. Price and margin approval are judgement, and they stayed with people. Configuration maths, document assembly and drawing production are repetition, and they became the system's job.

The drawing automation was proven against real assemblies, including a locker model of 654 components. The system is deployed and in staged handover to the sales team; specification sessions with the costing, sales and operations owners have driven successive rounds of scope, and it continues to change with the work.