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PDCA Cycle and SDCA Cycle | IT Passport Exam Prep

April 27, 2026

A breakdown of the differences between PDCA (Plan-Do-Check-Act) and SDCA (Standardize-Do-Check-Act), and how to use them for business improvement and quality management, tailored for the IT Passport exam.

TagsIT PassportStrategyPDCA

Differences Between PDCA and SDCA

PDCA is a business improvement cycle named after the initials of Plan, Do, Check, and Act. In contrast, SDCA starts with Standardize and aims to maintain and embed standards. The two cycles operate in tandem: standardized tasks are improved, and the results of those improvements are then established as new standards, repeating the process.

Steps of the PDCA Cycle

In the Plan phase, you set goals and plans and define KPIs. In the Do phase, you execute the plan. In the Check phase, you evaluate the results and measure the gap against the goals. In the Act phase, you analyze the causes and feed improvement ideas back into the next Plan phase.

The Role of SDCA

SDCA plays the role of embedding improved processes into standard on-site operations, reducing variability in work. This concept aligns with the continuous improvement framework of ISO 9001. Running PDCA alone without standardization leads to reliance on specific individuals, so it is important to operate SDCA and PDCA together.

Key Points for the IT Passport Exam

In the IT Passport exam, the order and meaning of each PDCA step are frequently tested. Additionally, the difference between PDCA and SDCA—specifically the contrast between improvement and standardization—is asked. Since these topics also appear in the context of quality management and continuous improvement in ITIL, try to learn them in relation to each other.

Typical Past Exam Question Patterns

  • "Which activity corresponds to the Check phase of PDCA?"
  • "Which statement correctly describes the purpose of SDCA?"

Related Terms

Study Tips

Distinguish PDCA as "Plan → Do → Check → Act" and SDCA as "Standardize → Do → Check → Act" by their initials. It is helpful to remember them by their verbs: "Improvement = PDCA, Maintenance = SDCA." For example, use PDCA when starting production of a new product, and SDCA when maintaining quality on an existing line.

Summary

PDCA and SDCA are complementary, understood as the two wheels of improvement and maintenance. For comprehensive practice on the Strategy domain, check out the Strategy Summary, and for a full-length practice test, use the Mock Exam.

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