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Problem Concentration Diagram

Quality Glossary Definition: Problem concentration diagram

The problem concentration diagram is a root cause analysis tool to help delve deeper into the possible causes and zoom in on the root cause by helping connect events to physical locations, thus perhaps revealing patterns of occurrence. The location where an event occurs may be important information. For instance, in which operating rooms do injuries occur? Which floors see fall accidents? The five whys technique and fault tree analysis also help narrow down the root cause, but a problem concentration diagram is the best tool to use if there is a geographical dimension to the event and its causes.

Problem Concentration Diagram Procedure

Create a problem concentration diagram through the following steps:

  1. Design the diagram by drawing a map of the building, area, or system.
  2. Determine whether location-based event occurrence data already exist. If yes, skip to step 4.
  3. If not, define what events are to be recorded and collect data linking events to locations.
  4. Where more than one event is recorded, assign symbols to each.
  5. Populate the diagram with the collected data by plotting the events on the diagram.
  6. Analyze the diagram to identify patterns of event occurrences.


A long-term care facility wanted to see whether patient falls occurred randomly throughout the facility’s buildings and outdoor area or were concentrated in some areas. The investigation team reviewed all reported falls during the last year, and the majority of reports described the location of the falls. Where the exact location was missing, in most cases, the team could deduce the location from the description of the fall.

Based on these data, the team produced a problem concentration diagram (Figure 1). The diagram was based on a rough sketch of the buildings and grounds, indicating types of rooms. The recorded falls were then plotted on this diagram, using stars to mark falls.

A clear pattern emerged, with bathrooms and bedrooms seeing the most falls (and even more specifically, the immediate surroundings of toilets and beds, respectively).

Figure 1: Problem Concentration Diagram Example
Problem Concentration Diagram Example

Excerpted from Root Cause Analysis and Improvement in the Healthcare Sector: A Step-by-Step Guide, ASQ Quality Press.

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