Most SPC software is built for an enterprise quality department: multi-site governance, role hierarchies, an implementation project and a five-figure annual commitment. If you run one line, all of that is overhead you pay for and never use.
Here is what one line actually needs.
The list, honestly
A handful of characteristics. Typically three to ten things that matter: a diameter, a wall thickness, a temperature, a torque figure. Not five hundred.
One or two chart types. X̄-R if you measure parts in batches, I-MR if you take one reading at a time. That covers nearly everything a single line does.
Limits that stay put. Computed once from a period when the process was behaving, then left alone. This is the difference between a control chart and a graph.
Somebody watching between shifts. Run rules evaluated continuously, and an email when one trips. On a single line there is rarely anyone whose job is to stare at charts.
A screen in the hall. The operator adjusting the machine is the person who benefits from the chart. If they cannot see it, the chart is documentation.
A way in for the data that is not typing. Whatever the gauge or CMM already exports, or a POST from the line's controller.
What one line does not need
- Multi-site comparison views.
- A governance layer over who may change limits.
- SAML, an SSO project, or per-site role hierarchies.
- An implementation consultant.
- Per-seat licences that make showing the chart to the floor a cost decision.
Every one of those is a reasonable thing for a group with twelve plants to want. None of them should be in the price of a single line.
What it should cost
Our Line plan is €169 a month: up to 25 characteristics, CSV import and the REST API, locked and versioned limits, and unlimited read-only viewers so the whole shift can see the chart.
For comparison, per-seat statistics licences generally start around four figures per user per year, and enterprise SPC platforms are quoted, not listed — which is usually a sign of where they expect the conversation to go.
Getting started without a project
- Sign up. No call, no card.
- Upload one CSV — whatever your gauge already exports. The file creates the characteristic; you do not have to model your factory first.
- Map the value and timestamp columns.
- Lock a baseline over a stable period.
That is a working chart, usually in under half an hour, and it is the whole onboarding. If your line already pushes data somewhere, the API takes readings directly:
curl -X POST https://api.spcvisuals.com/v1/measurements \
-H "Authorization: Bearer spc_live_..." \
-d '{"characteristic":"shaft-diameter","readings":[25.004,24.998,25.011]}'
When you outgrow it
Honestly: at a second plant, or when you need central control over who may re-baseline what. That is the Plant plan and it is worth a conversation. Until then, do not buy it.
Or look at five charts running on live public data first — no signup, and it is the same software.