In continual improvement, what are the four stages of the Deming Cycle that ITIL adopts for process and service improvement?

Introduction / Context:
The Deming Cycle, also known as the Plan Do Check Act cycle, is a foundational model for continual improvement used by ITIL in Continual Service Improvement and in the design of processes. This question asks you to recall the four stages of that cycle in the correct order, which is a common exam topic and a useful mental model for structured improvement work.

Given Data / Assumptions:

• The question refers explicitly to the Deming Cycle.
• ITIL reuses this cycle for continual improvement of services and processes.
• Different answer options contain variations of the four words.
• We must identify the canonical correct sequence.

Concept / Approach:
The Deming Cycle is a simple but powerful iterative model for quality improvement. Plan means define objectives and processes needed to deliver results in line with customer requirements. Do means implement the plan and execute the processes. Check means monitor and measure processes and services against policies, objectives, and requirements and report the results. Act means take corrective and improvement actions based on what was learned in the Check stage. ITIL uses this same cycle to drive continual service improvement across the service lifecycle.

Step-by-Step Solution:
Step 1: Recall that the Deming Cycle is commonly abbreviated as PDCA.Step 2: Expand PDCA into Plan, Do, Check, Act.Step 3: Compare this expansion with the options provided.Step 4: Select the option that exactly matches Plan, Do, Check, Act in that order.

Verification / Alternative check:
Any quality management or ITIL reference will show the Deming Cycle as Plan Do Check Act. Training materials for ITIL Continual Service Improvement often show diagrams labelled with these four stages and describe how they can be applied repeatedly to services, processes, and even individual improvement initiatives. This consistent usage across sources confirms that Plan Do Check Act is the correct sequence.

Why Other Options Are Wrong:
Option a replaces Do and Act with Measure and Monitor, which are activities but do not follow the standard Deming naming. Option b rearranges the words and uses React, which is not the standard term used in PDCA. Option c uses Audit instead of Check, and the order is Plan Do Act Audit, which is not the established cycle. Option e describes a different high level lifecycle style sequence that is not the Deming Cycle and is not labelled as such in ITIL.

Common Pitfalls:
People sometimes remember only the general idea of planning, doing, and then adjusting, and they mix up the order of Check and Act or substitute their own words. Another pitfall is to equate PDCA with one time projects, when in reality it is meant to be repeated continuously, especially in Continual Service Improvement. Memorizing the exact phrase Plan Do Check Act helps avoid confusion on exams and encourages a disciplined approach in real improvement work.

Final Answer:
The four stages of the Deming Cycle used for continual improvement in ITIL are Plan, Do, Check, and Act.