Desktop system
An internal desktop tool that replaces a critical spreadsheet
A process that matters runs on a spreadsheet several people edit at once. It works until it does not: figures disagree, someone overwrites a column, and the only person who understands the formulas is on leave.
Where it comes up
- Retail and merchandise planning
- Manufacturing and textiles
- Jewellery and trading
Constraints that usually apply
- The current spreadsheet cannot be switched off on day one, so both have to run in parallel
- Users are fast at the existing sheet and will judge the replacement on keyboard speed
- The rules in the formulas are the real specification, and some of them are wrong
- Reporting has to reconcile to the old numbers before anyone will trust the new ones
Stack
Architecture
- WPF desktop client with a dense, keyboard-first grid
- SQL Server database with row-level locking and an audit table
- Server-side calculation layer so the rules live in one place, not in each user's copy
- Excel import and export retained deliberately, for the round trips people will keep wanting
- Windows authentication mapped to role-based permissions
Illustrative interface, drawn to show the screens involved
A realistic build timeline
- Weeks 1–2
Shadow the process, extract the real rules from the spreadsheet, agree the data model.
- Weeks 3–5
Busiest screen built end to end, on real data, installed on a real machine.
- Weeks 6–10
Remaining modules, permissions, audit trail and reporting.
- Weeks 11–12
Parallel run against the spreadsheet, reconciliation, installer and update channel.
Indicative only. Real dates come out of discovery, and they move when your side is short of time as often as when ours is.
What you own at handover
All of it, and from day one rather than at the end. If you replaced us mid-project you would lose momentum, not assets.
- Repository, database scripts and migration history
- Signed installer and a documented release process
- Architecture and calculation-rules documentation
- Recorded walkthrough for future staff
Is this a real project? It is the kind of system we build. Here is exactly how we would approach yours.