Integral Logistics Management — Operations Management and Supply Chain Management Within and Across Companies

18.2.1 The Deming Cycle (PDCA Cycle) and the Shewhart Cycle

Intended learning outcomes: Produce an overview on The Shewhart cycle developed in statistical quality control. Present the Deming cycle. Describe quality management tasks in the Deming cycle.



The Deming cycle, also called the Plan, Do, Check, Act cycle (PDCA cycle, also known as PDSA cycle, where S stands for Study), was an early means of representing the task areas of traditional quality management. The cycle is sometimes referred to as the Shewhart / Deming cycle since it originated with physicist Walter Shewhart at the Bell Telephone Laboratories in the 1920s. W. Edwards Deming modified the Shewhart cycle in the 1940s and subsequently applied it to management practices in Japan in the 1950s.

The Shewhart cycle ([Shew03], p. 45) is defined in Figure 18.2.1.1.

Fig. 18.2.1.1       The Shewhart cycle developed in statistical quality control.

The Deming cycle ([Demi18], p. 88), shown in Figure 18.2.1.2, is the application of the Shewhart cycle. 

Fig. 18.2.1.2       Quality management tasks in the Deming cycle.

Figure 18.2.1.3 describes in greater detail the logical sequence of the four cyclical tasks in the spirit of continuous quality improvement. These four cyclical tasks entailed a synonym of the term Deming cycle, namely PDCA cycle.

Fig. 18.2.1.3       Description of quality management tasks in the Deming cycle.

The fourth task in particular gives an indication of why, in total quality management, this same model is applied not only to systems in the value chain, but also to systems that impact stakeholders (see Figure 1 of the Introduction). In those cases, the behavioral aspect — that is, making the changes a routine part of activity — has special significance (here see Section 18.3).




Course section 18.2: Subsections and their intended learning outcomes

  • 18.2 Quality Management Tasks at the Operations Level

    Intended learning outcomes: Produce an overview on the Deming Cycle (PDCA Cycle) and the Shewhart Cycle as well as the Six Sigma Phases. Present the phases of quality planning, control, assurance, and activation of the Deming Cycle. Describe the Six-Sigma phases of define, measure, analyze, improve, and control. Differentiate between continual improvement and reengineering.

  • 18.2.1 The Deming Cycle (PDCA Cycle) and the Shewhart Cycle

    Intended learning outcomes: Produce an overview on The Shewhart cycle developed in statistical quality control. Present the Deming cycle. Describe quality management tasks in the Deming cycle.

  • 18.2.2 DMAIC — The Six Sigma Phases

    Intended learning outcomes: Present DMAIC, the Six Sigma phases. Describe the tasks in the Six Sigma phases. Differentiate between DMAIC, RDMAIC, DMAICT, and DMADV.

  • 18.2.3 Quality Planning: PDCA Plan Phase — DMAIC Define Phase

    Intended learning outcomes: Identify the cause of differences between stakeholders’ expectations and actual product or process characteristics. Explain quality function deployment – the house of Quality and 10 steps of implementation. Describe the SIPOC diagram and the CTQ matrix.