Rabbit Chase

A method of staffing a production cell so that each worker performs all tasks from beginning to end while "chasing" the other people working ahead of them in the cell. The aim is to increase or reduce output by adding or removing people from the cell, without requiring a rebalancing or adjustment of work assignments to each person.

RACI chart

A chart clarifying the responsibility of project team members. RACI stands for Responsible, Accountable, Consulted, Informed. These responsibilities are:

  • R = Responsible: Complete the task. Every task must have at least one R.
  • A = Accountable: Delegate work and review the task or deliverable upon completion. Every task must have at least one A. The A may be the same as the R.
  • C = Consulted: Provide input based on expertise or knowledge of how it will impact future project work.
  • I = Informed: Be kept in the loop on project progress but not on all details.

Radar Chart

A graph visualizing three or more variables of multivariate data, in thee shape of the two-dimensional chart that resembles the a weather radar display. Data are represented on axes starting from the same central point. The central point represents the lowest value and the outside edge of the radar chart represents the maximum value.

Random Sampling

The selection of a sample so that there is no pattern or predictability to how each item is selected. A sample such that each item in the population has an equal chance of being selected.

Rapid Improvement Event

Rapid Improvement Workshop

Red Tag

Pieces of red paper used during the first 5S step of sorting.

Red X

A dominant cause that is a major contributor to variation that must be remedied for problem resolution.

Red X was coined by Dorian Shainin.

Regression Analysis

The estimation of the relationships between different variables by examining the behavior of the system. Regression analysis allows for making predictions based on data and for measuring whether results align with what is expected when a variable in a process is changed. It is commonly used during the Analysis phase of DMAIC.

Relationship Diagram


The ability for a process, test or measurement to produce identical results again and again by the same person.


The ability of the output of a process to be duplicated by multiple people.

Respect for People

The foundational principle of Lean that emphasizes engaging people, developing people, and making the workplace better for people. One of the two core elements of the Toyota Way, along with continuous improvement.

Results Metric

Measurements to evaluate the financial performance of business.

See also Lagging Indicators

Responsibility Assignment Matrix


A practice used by Agile teams to periodically reflect on their way of working and identify improvement actions. Retrospectives are typically held at the end of sprints. Also known as Sprint Retrospectives or Agile Retrospectives.

Right-Sized Equipment

Equipment that is designed, built and commissioned to fit the size and capability needed to produce a specific product. In contrast to purchasing large or over-powered equipment, right-sized equipment often has the bare minimum functionality to perform the process, reducing the capital cost, running cost and increasing flexibility.


A document that travels among stakeholders for comment, questions and approval of a project or a decision on specific issues requiring input from various stakeholders. The ringisho is a form of serial debate and discussion through written word that allows time to reflect on the information as well the comments of others.

Risk Priority Number

A number assigned to represent the risk to a process as part of Failure Modes and Effects Analysis (FMEA). The RPN is calculated as the product of the numeric values of individual failure modes and their likelihood of occurrence, ease of detection, and severity of impact.

Rolled Throughput Yield

The probability that a process with multiple steps will produce a defect-free output. Abbreviated RTY, it is calculated as the product of the yields for each process step in a series of processes.

Rolling Changeover

Performing changeovers or setups along a production line in process sequence in order to minimize downtime on the line.

See also Sequential Changeover

Root Cause

The cause at the earliest starting point of a causal chain that leads to an outcome

Root Cause Analysis

The use of various methods and tools to investigate and identify the root cause.

Run Chart

A line graph of data plotted over time. Run charts show trends or patterns in the process by collecting and plotting data over time. Run charts can show how the process is running but cannot show whether a process is stable because they do not use control limits. Run charts are valuable tool at the beginning of improvement projects as they show important information about a process before enough data has been gathered to set control limits.

Runners, Repeaters, Strangers

Classification of the behavior of products or services based on PQ Analysis to create the three bands where Runners are products with high volume and low variability, Repeaters medium demand, medium variability, and Strangers low demand, high variability.