SPC Control Chart Tracker

The problem this kills

You measure a key characteristic on the line - a bore diameter, a fill weight, a torque value - and you log it in a spreadsheet. But the spreadsheet just stores numbers. By the time someone eyeballs it and notices the process has been creeping for the last six subgroups, you've already made a tray of scrap.

Real statistical process control (SPC) catches the drift while it's happening. It plots each subgroup, draws control limits computed from your own process, and screams the moment a point falls outside the limits or a run of points trends one way. Most teams know they should do this. Almost nobody does, because the off-the-shelf SPC software is expensive, locked-down, and built for a quality department that doesn't exist at your shop.

This kills the gap: you build your own SPC tracker, tuned to the exact characteristic and subgroup size you actually run, and it watches the process for you.

What you'll build

A private, login-protected web app for your team that:

• Lets an operator record a subgroup of measurements (e.g., 5 parts sampled every hour) against an item and characteristic.
• Computes the subgroup mean (X-bar) and range (R) automatically.
• Calculates control limits from your data (not from the spec - that's the whole point of SPC) once you have enough subgroups.
• Plots a live X-bar & R control chart you can read at a glance.
• Runs standard run rules to detect out-of-control signals: a point outside the limits, a run of points on one side of center, and a steady trend up or down.
• Shows process capability (Cp / Cpk) against your spec so you know if the process is even capable of meeting the requirement.
• Emails an alert the moment a signal fires, then routes it to a quality engineer who reviews and approves the response note before it's logged as addressed.

What's inside the Implementation Plan

The plan is a complete, paste-and-go runbook. The first thing it does is interview you about your process - what you measure, your subgroup size, your sampling cadence, your spec and target, how your part and characteristic codes are named, and the messy exceptions (re-measured parts, tool changes, shift handoffs). It reflects a short tailored spec back to you and waits for your thumbs-up before it builds anything. The tool you get fits your process, not a generic demo.

From there it walks you, prompt by prompt, through standing up the database, the login, the measurement-entry screen, the math (X-bar/R, control limits, Cp/Cpk), the chart, the run-rule detector, the email alerts, and the engineer approval gate - each step ending in a ready-to-paste prompt.

The governance it includes (this is the point)

This isn't a toy. Every runbookify plan builds in the controls a real shop floor needs:

• Login so only your team can see or touch the data.
• Row-level security so each organization only ever sees its own measurements.
• A full audit trail - who logged each subgroup, who acknowledged each alert, and when.
• A human-in-the-loop approval gate - the app detects and drafts, but a quality engineer reviews every out-of-control signal and approves the response note before it's logged as addressed. The AI never closes an issue on its own.
• Duplicate guards so the same subgroup (same characteristic + timestamp) can't be logged twice.

Who it's for

Quality engineers, process engineers, and line operators on any monitored process - machining, molding, filling, assembly, packaging - who want real-time SPC without buying enterprise software.

You've got this. Paste the first prompt and let the agent interview you.