Knowledge Base · Tools & Terms
What is a run chart, and how do I read one?
A run chart plots one measure in time order so the trend is visible at a glance. Read direction and sustained shifts after a change, not single points: Chapter 5 of the book judges improvement on trends, and treats one flattering data point the way it treats premature celebration.
A run chart is the simplest honest picture of a process over time: the measure you care about, plotted in time order, one point per day, week or case, connected by a line. Chapter 5 of the book builds its whole measurement approach on this kind of picture, because improvement is judged on trends, and a trend is the one thing a run chart shows and a single number cannot.
Reading one is mostly discipline. Look first at direction: is the line drifting up, down, or wandering around a level? Look for a sustained shift after a known change: did the line move when the new process started, and did it stay moved? That pattern, points consistently on a new level after the change, is what a working improvement looks like. A single spike, good or bad, is weather, not climate, and the book's advice is to react to the pattern and not the point.
Watch for the two reading errors the book warns about in other forms. Celebrating one good point is the premature-celebration trap in miniature. And a long flat line at a good level is not a reason to relax; in Chapter 7's terms it is where complacency sets in, and the question becomes what the next improvement is.
Keep run charts where the huddle board lives, updated by the team, one per key measure. Paired with the book's red-means-gold posture, they turn measurement from a reporting chore into the team's own early-warning system.
Related questions
- How should I react when a metric turns red?
- What is visual management?
- What are the four tests of a good KPI?
Source: Continuous Improvement in the Workplace, Ch. 5 (Measuring Success and Ensuring Sustainability).