A cause-and-effect diagram, also known as a fishbone or Ishikawa diagram, should be completed. Root cause analysis is used to discover the factors contributing to an identified problem and involves capturing information from all stakeholders involved, such as by asking each involved individual why he or she believes the problem may be occurring. However, this potentially large amount of information needs to be organized in a logical manner to enable meaningful conclusions to be drawn in order to address the problem. A cause-and-effect diagram is used to organize the root causes of a problem; the problem, or system process, forms the backbone of the diagram, and root causes are branched off (like ribs of a fish). For example, the quality team in this case may complete a root cause analysis to determine why the rate of urinary catheter–associated infections is high (the backbone). After interviewing the physicians, nurses, desk staff, and patients, potential root causes are identified and recorded (the ribs). Examining these potential causes, such as the absence of a protocol for discontinuing urinary catheters, relative to the problem helps identify the nature of the contributing factors and their location within the care process. Organizing root cause information in this way may provide a clearer assessment of specific system issues and interventions that may help address the problem and effect system change.

A control chart is used in quality improvement to graphically display variation in a process over time and can help determine if variation is from a predictable or an unpredictable cause. Additionally, control charts can be used to determine if an intervention has resulted in a positive change. For example, the rate of medication errors could be tracked before and after the initiation of a computer physician order system to determine if the system has had an impact on reducing errors.

A Pareto chart is another method for organizing root causes by displaying them on a graph in descending order of frequency. Unlike a fishbone diagram that is used to identify potential causative factors of a problem and the potential relationship between different variables, Pareto charts are more helpful in focusing improvement initiatives on the most common root causes of a problem.

Spaghetti diagrams are used to visually display flow through a system. The flows are drawn as lines on a map and look similar to spaghetti noodles. For example, a spaghetti diagram may be used to follow a medication order through a hospital unit from order generation to administration of the medication. The diagram can help highlight inefficiencies or redundancies in a system.