Playbook · v1.0
The Editable Rules Pattern.
A FileMaker + AI playbook.
Turn hardcoded business rules buried in your FileMaker calcs into a client-editable lookup table. The owner tunes the thresholds; the calc never breaks; you stop fielding "change this number" emails.
12-page illustrated PDF methodology + working .fmp12 starter file. Built and validated on a 30-year production system.
Instant download · PDF + .fmp12
The problem
Your business rules are stuck inside your calcs.
Most FileMaker solutions have business rules baked into their formulas — pricing tiers, status flags, scheduling cutoffs, approval thresholds. The numbers that drive day-to-day decisions are buried inside a calculation field where only a developer can touch them.
The business owner reads the output. They can't tune the logic. Every threshold change becomes a support ticket. They lose trust in the system; you lose hours on micro-edits that don't justify a bill.
The pattern
One small lookup table. Plain-English labels. Blank means skip this rule.
Surface the thresholds as records in a small lookup table. Give the owner a layout they can read at a glance. Wire the parent calc to read its values from the table with an IsEmpty()-guarded fallback so blank cells go dormant rather than break the calc.
Developer-encoded judgment of "what counts as RUSH / URGENT / EMERGENCY" becomes the owner's judgment, applied automatically, tunable without a developer in the loop.
See it in action
Same date. Different rules. Different flag.
Two orders. Same promised date (6/6/2026). One flagged RUSH; one flagged STANDARD. The difference: their rule rows. The EMERGENCY_WATCH row deliberately left its RUSH and URGENT thresholds blank — the calc treats blank as "skip this rule." One customer chose less noise; the system honors it. No developer touched anything.
The implementation
One Let block. One Case statement. Safe under every failure mode.
The whole pattern lives in a single calc. Read each threshold from the rules table; if blank, fall back to a sentinel value that no input can reach. Severe-first Case branches return the right flag every time.
Missing rule row, blank field, typo'd join key — all safe. The playbook walks you through the 8 gotchas that aren't obvious until they bite. Calc text in the starter file is yours to copy.
What's in the bundle
Methodology + working file. Open and study, then adapt.
-
Playbook_Editable_Rules_Pattern.pdf
12 illustrated pages walking the methodology in three phases — Discovery & Design (Steps 1-3), Build (Steps 4-7), Ship & Handoff (Steps 8-10). Annotated screenshots from the working starter file at every Build step. Plus a Gotchas section covering 8 traps that will bite you, a Tooling section, Adaptation notes for 6 different domains (pricing, inventory, approval workflows, customer health, SLA, scheduling), and a Going Further appendix for AI-assisted iteration.
-
RulesPattern_Starter_v1.fmp12
A fresh-build starter file wired end to end. Two tables (Orders + UrgencyRules), one read-only lookup relationship, two demonstration calcs with the
IsEmpty()-guarded fallback structure, two polished layouts with cross-navigation, seed data showing all four flag states plus the blank-skip pattern. ProofKit'sConnect to MCPscript pre-installed so the file is AI-ready out of the box. Adapt by rename.
Commercial use included. Lifetime updates. License terms in the PDF.
Who this is for
- FileMaker developers shipping rule-driven business logic to non-developers.
- Consultants who hit "change this number" requests after every release.
- Anyone with a client whose owner reads the output but can't tune the logic.
- Devs who want a defensible pattern to reach for in the next engagement.
Who this is not for
- Anyone new to FileMaker — this assumes fluency in tables, calcs, relationships.
- Someone hoping for an AI assistant that builds the file for you.
- Buyers expecting a turn-key system, not a methodology.
- Anyone whose rules need to NEVER be operator-editable (regulatory, safety-critical).
FAQ
What FileMaker version do I need?
FileMaker Pro 19 or later. The pattern uses functions that have been around for a decade, but the starter file was built and tested on the current major release.
Can I use this in client projects?
Yes. Commercial use is included in the license. Adapt the pattern, ship it in your client work, charge what you charge. The license only prohibits reselling the playbook PDF or starter file as-is.
Is ProofKit required to use the starter file?
No. The .fmp12 works as a plain FileMaker file — open it, study it, copy from it. ProofKit is wired in for buyers who want to extend the pattern with AI assistance (instructions in the playbook's Going Further appendix), but it's optional.
What about updates?
Lifetime updates included. When v1.1 ships (new gotchas, refined examples, expanded adaptation notes), every buyer gets the new version automatically.
Refunds?
If the playbook doesn't help and you can tell me why, I'll refund within 30 days. I'd rather hear what didn't land than keep the $199.
Save yourself the trial-and-error.
The pattern is proven in production. The starter file is wired and working. The playbook walks the steps and the traps. Pay for the shortcut.
Instant download · PDF + .fmp12