Approach Selection Based on Safety Requirements
PMBOK v8 Definition
Products that have rigorous safety requirements often use a predictive approach as there is a need for significant up-front planning to ensure safety compliance. A predictive approach (also referred to as waterfall, plan-driven, or traditional) may be optimal when the project scope can be stabilized early. This approach is also suitable for large projects involving significant investment or regulatory oversight, requiring robust change control mechanisms and planned reevaluation between successive phases.
Why It Matters for the Exam
The PMI exam frequently tests your ability to select the correct development approach based on project characteristics. Safety requirements are a determinant factor in choosing between predictive, adaptive, or hybrid approaches. Expect scenario-based questions where you must identify that rigorous safety requirements demand a predictive approach due to the need for extensive upfront planning, documentation, and compliance demonstration.
Key Points to Remember (for the exam)
- Primary Driver: Rigorous safety requirements → Predictive approach is optimal
- Reason: Significant up-front planning is needed to ensure safety compliance
- Scope Stability: Predictive approach requires scope that can be stabilized early in the project
- Change Management: Predictive approaches require robust change control mechanisms
- Regulatory Overlap: Environments with significant regulatory oversight also favor predictive approaches due to required processes, documentation, and demonstration needs
- Contrast with Adaptive: Adaptive approaches are optimal when there is significant value from frequent feedback or when scope is unstable
- Hybrid Reality: Most projects today benefit from a hybrid approach, but safety-critical projects lean heavily toward predictive
Typical PMI Exam Example
You are managing a project to develop a medical device that must comply with FDA safety regulations. The scope is well-defined, and changes are costly and difficult to incorporate. Which development approach is most appropriate?
Answer: Predictive approach, because rigorous safety requirements and regulatory oversight necessitate significant up-front planning and robust change control.
PMI Exam Traps
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Trap: Assuming adaptive approaches are always better for managing risk Reality: Adaptive approaches help manage uncertainty, but safety requirements (a specific risk category) favor predictive approaches
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Trap: Confusing "safety requirements" with "risk management" Reality: Safety requirements are a specific factor that drives approach selection; risk is a separate consideration in Section 4
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Trap: Thinking hybrid means 50/50 split between predictive and adaptive Reality: Hybrid exists on a spectrum (Levels 1-3), and safety-critical projects typically remain strongly predictive with only minor adaptive elements
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Trap: Selecting adaptive approach because deliverables can be modularized Reality: Modularization supports hybrid approaches, but safety requirements override this consideration—predictive is still required
Important PMI Connections
| Related Concept | Relationship Type | Exam Attention Point |
|---|---|---|
| Regulatory Oversight | Complements safety requirements | Both drive predictive approach; regulations add documentation and demonstration needs |
| Scope Stability | Prerequisite for predictive | Stable scope enables predictive; unstable scope pushes toward adaptive |
| Change Control | Mechanism within predictive | Robust change control is required when changes are difficult/costly |
| Delivery Cadence | Output of approach selection | Section 4.4 links approach to delivery cadence; predictive uses phased delivery |
| Risk Management | Separate consideration | Adaptive helps manage uncertainty; predictive manages safety compliance risk |
Quick Review Questions
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A project involves developing an aircraft navigation system with strict safety certifications. The scope is well-understood. Which development approach should be selected?
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What is the primary reason that rigorous safety requirements favor a predictive approach over an adaptive approach?
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How does regulatory oversight relate to safety requirements in determining the development approach?
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In what situation would a hybrid approach be appropriate for a project with safety requirements?
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True or False: Adaptive approaches are always better for managing project risk.
PMBOK v8 Reference
Section 4.2 – Development Approaches and Life Cycles (specifically Section 4.2.1 Predictive Approaches and the factors listed in Section 4 – Project Life Cycles)