Preliminary Design Review Guidelines

Understanding Preliminary Design Reviews in Defence Engineering

In the complex landscape of defence engineering, the Preliminary Design Review (PDR) stands as a critical milestone that separates conceptual exploration from detailed design commitment. For engineering firms operating in Atlantic Canada's growing defence sector, mastering the PDR process is essential for delivering successful military and security-related projects that meet the stringent requirements of the Department of National Defence (DND) and allied forces.

A well-executed PDR serves as the gateway between the system definition phase and detailed design, ensuring that proposed solutions are technically sound, financially viable, and aligned with operational requirements. For Nova Scotia's defence contractors and engineering consultancies, understanding these guidelines is particularly relevant given the region's expanding role in shipbuilding, aerospace support, and military infrastructure development.

Core Objectives and Success Criteria for PDR

The fundamental purpose of a Preliminary Design Review is to establish confidence that the preliminary design meets all system requirements with acceptable risk and within cost and schedule constraints. This milestone review typically occurs when the design is approximately 30-35% complete, providing sufficient detail to validate the approach while allowing flexibility for refinements.

Primary PDR Objectives

• Technical Baseline Validation: Confirm that the preliminary design satisfies all allocated functional and performance requirements derived from the System Requirements Review (SRR)

• Risk Assessment: Identify and evaluate technical, cost, and schedule risks with corresponding mitigation strategies

• Resource Verification: Ensure adequate resources, facilities, and personnel are available for detailed design and subsequent phases

• Interface Definition: Verify that all internal and external interfaces are properly defined and controlled

• Manufacturing Feasibility: Confirm that the design can be produced using available manufacturing processes and technologies

Measurable Success Criteria

Defence projects in Canada typically require quantifiable success criteria aligned with Treasury Board guidelines and DND's Project Approval Directive. Common metrics include:

• Minimum 95% of performance requirements demonstrably allocated to design elements

• Technical Performance Measures (TPMs) tracking within 10% of target values

• Risk retirement rate achieving at least 60% of identified high-priority risks addressed

• Cost estimates accurate to within ±15% at the subsystem level

• Schedule confidence level of 70% or higher based on integrated master schedule analysis

Documentation Requirements and Deliverables

Comprehensive documentation forms the backbone of any successful PDR. For defence engineering projects, documentation must comply with Canadian Defence Administrative Orders and Directives (DAODs) as well as applicable NATO Standardisation Agreements (STANAGs) when international interoperability is required.

Essential PDR Documentation Package

The following documents should be prepared and distributed to review participants at least 14 calendar days prior to the scheduled review:

• System Specification: Updated to reflect preliminary design decisions and trade study outcomes

• Preliminary Design Drawings: Including general arrangement drawings, schematics, and interface control documents at minimum 1:50 scale for structural elements

• Analysis Reports: Structural, thermal, electromagnetic compatibility (EMC), and reliability analyses appropriate to the design maturity level

• Trade Study Reports: Documentation of alternative approaches considered and rationale for selected solutions

• Risk Register: Comprehensive listing of technical, programmatic, and external risks with probability and consequence assessments

• Verification Cross-Reference Matrix (VCRM): Tracing requirements to verification methods and planned verification events

• Technical Performance Measurement Report: Current status of all tracked TPMs with trend analysis

Canadian-Specific Documentation Considerations

Defence projects in Canada must address bilingual documentation requirements under the Official Languages Act. Technical specifications, safety warnings, and operator-facing documentation typically require both English and French versions. Additionally, projects involving controlled goods must comply with the Controlled Goods Program (CGP) administered by Public Services and Procurement Canada, with appropriate security classifications and handling procedures documented.

Review Board Composition and Roles

The effectiveness of a PDR depends significantly on assembling a review board with appropriate expertise and authority. For defence engineering projects in the Maritime provinces, this often involves coordination between multiple stakeholders including DND project management offices, prime contractors, and specialised engineering consultancies.

Recommended Review Board Structure

A typical PDR board for medium-complexity defence systems should include:

• Review Chairperson: Senior technical authority independent from the design team, typically with 15+ years of relevant experience

• Systems Engineering Representative: Responsible for requirements verification and interface assessment

• Discipline Engineers: Subject matter experts in mechanical, electrical, software, and human factors engineering as applicable

• Quality Assurance Representative: Ensures compliance with ISO 9001:2015 and AS9100D standards common in defence aerospace applications

• Integrated Logistics Support (ILS) Representative: Evaluates maintainability, supportability, and lifecycle cost implications

• Customer Technical Authority: DND representative with authority to accept or reject design approaches

• Configuration Management Specialist: Verifies baseline establishment and change control readiness

Conflict of Interest Management

Review board members should declare any potential conflicts of interest prior to the review. Canadian government contracting regulations require that individuals who participated directly in concept development or proposal preparation should not serve as independent reviewers. This separation ensures objective assessment of design adequacy.

Technical Assessment Areas and Evaluation Methods

A thorough PDR examines the preliminary design across multiple technical dimensions. Each assessment area requires specific evaluation methods and acceptance criteria tailored to the project's complexity and risk profile.

Functional and Performance Analysis

The review team must verify that the preliminary design demonstrates the capability to meet all allocated requirements. This includes:

• Functional flow analysis confirming all operational modes and states are addressed

• Performance budgets showing adequate margin (typically 10-20% depending on technology maturity)

• Environmental qualification planning for temperature ranges (-40°C to +50°C for Canadian military equipment), humidity, vibration, and shock per MIL-STD-810H or equivalent

• Electromagnetic compatibility analysis per MIL-STD-461G for military systems operating in the North Atlantic environment

Reliability, Maintainability, and Availability (RMA) Assessment

Defence systems must demonstrate lifecycle supportability appropriate to Canadian Armed Forces operational concepts. Key metrics evaluated at PDR include:

• Mean Time Between Failures (MTBF) predictions based on MIL-HDBK-217F or equivalent reliability prediction methods

• Mean Time To Repair (MTTR) estimates supporting operational availability requirements

• Maintenance task analysis identifying scheduled and unscheduled maintenance requirements

• Support equipment and test equipment requirements definition

Safety and Environmental Compliance

Canadian defence projects must comply with the Defence Administrative Orders and Directives on safety management (DAOD 7002 series) as well as environmental protection requirements. The PDR should address:

• Preliminary hazard analysis (PHA) identifying potential safety hazards and proposed controls

• Environmental impact assessment for manufacturing, operation, and disposal phases

• Compliance with the Canadian Environmental Protection Act and applicable provincial regulations in Nova Scotia

• Hazardous materials identification and management planning

Common Deficiencies and Best Practices for Resolution

Experience from defence engineering projects across Atlantic Canada reveals recurring deficiencies that can delay PDR approval. Understanding these common issues enables project teams to address them proactively.

Frequently Identified Deficiencies

• Incomplete Requirements Traceability: Approximately 40% of PDRs identify gaps in the requirements verification matrix, often due to late requirements changes not fully flowed down to design elements

• Inadequate Interface Definition: Interface control documents lacking sufficient detail for external system integration, particularly common in multi-contractor programmes

• Optimistic Risk Assessments: Underestimating probability or consequence of technical risks, especially for novel technologies or Canadian-specific environmental conditions

• Insufficient Design Margin: Performance predictions showing less than 10% margin against requirements, leaving inadequate buffer for detailed design refinements

• Immature Software Architecture: Software-intensive systems often lag in architectural definition compared to hardware elements

Proven Resolution Strategies

Successful defence engineering programmes employ several strategies to address PDR deficiencies efficiently:

• Conduct internal "murder boards" two to three weeks before formal PDR to identify and resolve issues early

• Establish clear action item tracking with responsible individuals and realistic closure dates

• Implement rolling wave planning to address near-term issues while acknowledging longer-term resolution paths

• Engage customer technical authorities in informal design discussions before formal review events

• Utilise digital engineering tools for requirements management and design verification to improve traceability

Post-PDR Activities and Transition to Detailed Design

Successful completion of the PDR authorises transition to the detailed design phase, but several critical activities must occur during this transition period to maintain programme momentum and technical integrity.

Immediate Post-PDR Requirements

Within 30 days of PDR completion, the following activities should be accomplished:

• Publication of final PDR minutes documenting all decisions, action items, and agreed-upon design baseline

• Closure of all Category I action items (those required before detailed design can proceed)

• Establishment of the allocated baseline under formal configuration control

• Update of the Integrated Master Schedule reflecting PDR outcomes and any approved schedule adjustments

• Communication of design decisions to all affected suppliers and subcontractors

Continuous Improvement Integration

Defence engineering firms committed to excellence should capture lessons learned from each PDR experience. This includes documenting what worked well, identifying process improvements, and updating internal procedures to enhance future review effectiveness. For firms operating in Nova Scotia's defence sector, sharing non-proprietary lessons learned through industry associations such as the Aerospace and Defence Industries Association of Nova Scotia strengthens the regional industrial base.

Partner with Sangster Engineering Ltd. for Defence Engineering Excellence

Successfully navigating Preliminary Design Reviews requires deep expertise in defence engineering processes, comprehensive understanding of Canadian regulatory requirements, and proven experience delivering complex technical programmes. Sangster Engineering Ltd., based in Amherst, Nova Scotia, brings decades of professional engineering experience to defence and security projects throughout Atlantic Canada and beyond.

Our team understands the unique challenges facing defence contractors in the Maritime region, from meeting stringent DND requirements to addressing the environmental conditions specific to North Atlantic operations. Whether you require support with PDR preparation, independent design review services, or comprehensive systems engineering throughout your programme lifecycle, Sangster Engineering Ltd. offers the technical depth and professional commitment your project demands.

Contact Sangster Engineering Ltd. today to discuss how our defence engineering expertise can strengthen your preliminary design review process and position your programme for success. Let us help you achieve technical excellence while meeting the cost and schedule expectations of your defence customers.

Partner with Sangster Engineering

At Sangster Engineering Ltd. in Amherst, Nova Scotia, we bring decades of engineering experience to every project. Serving clients across Atlantic Canada and beyond.

Contact us today to discuss your engineering needs.