Poka-Yoke Proofing in Non-Manufacturing’ Systems

Table of Contents


Quality as a means of creating and sustaining a competitive advantage has been widely adopted by both manufacturing and non-manufacturing organizations. This strategic stance has been fuelled by the growing attention to strategic quality arising from the international successes of Japanese and other South Eastern Asian countries. Poka Yoke is one of the approaches to quality which helps organizations to avoid errors and mistakes by putting certain limits on operations. Traditionally, Poka Yoke is used in manufacturing as a part of the total quality management (TQM). Thus, Poka Yoke can be successfully applied to and used in manufacturing organizations.

Definition of the Concept

The concept of Poka Yoke was developed by a Japanese engineer, Shigeo Shingo. Poka Yoke can be described as “a formidable tool for achieving zero defects and continually eliminating quality control inspections” (Shimbun 1988, p. xi). The main task of Poka Yoke approach is to improve quality and help organizations plan their efforts. An organization’s ability to change continually and learn to innovate in relation to the changing marketplace is also a key issue for Poka Yoke approach. The main elements of Poka Yoke involve: (1) “source inspection to detect errors at their source; (2) 100% inspection for defects using an inexpensive sensing device such as a limit switch; (3) immediate actions to stop operations when an error is detected” (Shimbun 1988, p. xii). Thus quality improvement efforts are prioritized and focused. Shigeo Shingo identifies three main methods of Poka Yoke: (1) the contact methods; (2) the fixed value methods; and (3) the motion step method (Shimbun 1988). These methods are used for determining the optimal process or/and product parameter settings that reduce variation in the functional performance of products around its desired target value. In order to accomplish this objective, one may need to identify the key parameters which have significant impact on the mean process performance and performance variability through carefully inspection and control of all defects and errors (Shingo, 1985). Ppka Yoke domain expands to beyond production to include every activity in which an organization engaged.

Poka Yoke Benefits for Ritz-Carlton Hotels

It is important to note that Poka Yoke can be applied to the service industry as long as the output performance can be identified and measured accurately. Ritz-Carlton Hotels belong to hospitality industry. Quality of customer service and guests satisfaction is the main industry requirements which help hotels to compete and remain profitable. In this industry, the external connotations of quality change as well to reflect its indispensable role in corporate strategy formulations (Shingo, 1986). Ritz-Carlton Hotels can use Poka Yoke techniques as a formidable competitive weapon, that with appropriate focusing on customer satisfaction, could make organizations and improve service delivery. In Ritz-Carlton Hotels, quality is viewed as merely conforming to specification. This view of quality in organizations must be a first step, not a final goal. The objective of Poka Yoke techniques is to reduce the variation of the service functional performance characteristic about their target levels (Shimbun, 1988).

Areas of Improvements

In Ritz-Carlton Hotels Poka Yoke techniques can be applied to all service operations including billing and collections, housekeeping, reservations, supervision, customer communcation, etc. For instance, using Poka Yoke techniques Ritz-Carlton Hotels can update services; minimize the time to respond to customer complaints; minimize errors on service orders; reduce the service delivery time to customers (e.g. banks, restaurants etc.); reduce processing errors in transactions at banks; reduce waiting time at the check-in counter of an airport; minimize the number of billing errors from a utility company. As the most important, Poka Yoke techniques can be used as a part of Failure Mode and Effects (FMEA) and help to prevent and avoid possible errors in future (Shimbun, 1988). For instance, if a new service is implemented (such as online interaction or online billing), Ritz-Carlton Hotels can predict and foresee possible threats and errors using the motion step method or the value-fixed method. As a part of FMEA, Poka Yoke techniques will help to examine, analyze and prevent potential failures in a service system.

A Framework

Implementation of Poka Yoke within a service organization like Ritz-Carlton Hotels can be based on four steps. The first step is selection of the service process for Poka Yoke. It can be billing operations or customer support service. During this step, it is important to identify processes influenced by human errors and influenced by technical errors. Further, Poka Yoke techniques will help to lower the rating of occurrence. For service organization, the selection of an appropriate quality characteristic from the customers’ point of view is critical to the success. The selection of characteristics to measure quality as outputs immensely influences techniques that selected for inspection (Shimbun 1988).

The second step is selection of Poka Yoke’s techniques. In non-manufacturing sector, all three methods can be used. Following a contact method, the company can identify where or not ‘the service agreement’ is followed by employees. The fixed value method will help to examine a number of actions made by employee and their quality in relation to the service delivered to a customer. The motion step method will help to examine the quality of prescribed actions in service delivery. The main criteria for methods selection is low cost, easy to use and effectiveness of errors detection. Also, the management should pay a special attention to problem recognition and formulation as crucial for the success. It is important to ensure that the problem at hand requires Poka Yoke’s techniques to improve quality and avoid errors. A clear and succinct statement of the problem contributes substantially to a better understanding of the problem (Shimbun, 1988).

The third step is analysis of the results. The company should identify the source of errors. Errors can occur because: (1) “required action is NOT performed or is performed incorrectly; (2) undesired action is exercised; (3) information essential for performing the action is misinterpreted; (4) mistake occurs due to complexity” (Walimbe, 2007).

The forth step is 100 % detection of the error and its elimination. In this case, interpretation is useful to assist people with limited expertise in understanding the results and to take necessary actions on the design/process. Having interpreted the data, it is advisable to ensure that the conclusions are supported by the data (Walimbe, 2007).

The fifth step is to monitor and judge the effectiveness of the Poka Yoke’s techniques. The methods of judgment should be specific, measurable and must yield practical value to the company. The team approach encourages unbiased objectives of the techniques. The team may include a service specialist and a quality manager.


Poka Yoke can be successfully applied to non-manufacturing environment as one of the main quality methods. The advantage of this method for non-manufacturing organizations is that quality initiatives become the notion of a comprehensive approach where quality is an integral part of operations involving every employee of the company, as well as external operating practices. Poka Yoke requires a strong senior management commitment to, and responsibility and support for, the achievement and maintenance of a quality system, controls and inspections. Poka Yoke establishes a system of continuous process improvement which ensures the steady commitment and ongoing involvement of all employees.


  1. Shimbun, N.K. 1988, Poka-Yoke: Improving Product Quality by Preventing Defects Productivity Press.
  2. Shingo, Sh. (transl. by Dillon A.P.). 1986, ZQC: Source Inspection and the Poka-Yoke System. Productivity Press, Incorporated
  3. Walimbe, K. 2007, Work Instructions for Mistake Proofing.