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    28 October 2025•3 min read

    When to Set a Baseline on an SPC Chart

    Setting a baseline locks in your current performance so you can measure the impact of any process change clearly and fairly.

    One of the most powerful features in EasySPC Pro is the ability to set a baseline. A baseline freezes your control limits at a point in time so the chart can show what happens after a deliberate change.

    Why baselines matter

    Without a baseline, every new data point quietly recalculates your limits, which means a real improvement can be hidden inside the control limits over time. With a baseline, the impact of an intervention is clear: points that move below or above the original limits show that the process has genuinely shifted.

    When to use it

    • Before launching a process improvement initiative.
    • When you've changed equipment, staffing, or a workflow.
    • When you want to demonstrate to stakeholders whether a change has made a measurable difference.

    Refreshing your limits

    Once you have evidence that the new way of working has stabilised, you can recalculate the limits in EasySPC with a single click to begin monitoring the new normal.

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