Ready to Start Your Expert Review Services?
Contact AEi Systems today for a free consultation or quotation.Pre-WCCA Design Review
Early Issue Detection & Cost Savings
The Pre-WCCA circuit design review identifies design issues and possible non-compliances that would likely arise during the execution of a worst case circuit analysis. The review eliminates design issues and highlights WCCA findings early on so they can be fixed when there is time, saving you budget and schedule.
AEi Systems brings decades of WCCA experience to bear on finding problems in analog, digital, and RF circuitry. We highlight the potential and certain worst case failures allowing you to fix them before the formal WCCA is performed. We review vendor supplied simulation models in order to determine which ones are adequate (usually very few) and what their flaws are. We determine which circuit tests should be performed in order to support the WCCA, models, and circuit correlation and verification. We develop a WCCA plan and help you save money by prioritizing and/or eliminating unnecessary and costly analysis. We guide you by reviewing flow-downs and guidelines and making sure you do only the analysis that is value-added and required.
“The pre-WCCA design review is one of AEi Systems most valuable services.”
The Review Produces
- A WCCA plan
- A budget and schedule
- Prioritized list of analyses and analysis recommendations that should be performed
- A review of the key analysis guidelines and what they mean to your design and organization
- Resource definition: who needs to perform the analysis and what skills they should have
- Lists of models that are needed for the analysis including what model characteristics must be correlated
- Test data necessary to correlate models
- Suggested test point list to support the design, findings and WCCA
- Tolerance Database including a list of aging and radiation tolerances needed
Sample Analysis Findings
- Hard to see End-of-Life, Temperature, and Tolerance Stack-up issues
- Regulator Violations: Stability, Latch-up, Headroom, PDN, Loading and Compensation
- Opamp Violations: Stability, Common-Mode
- Bad SPICE Models
- Relay Usage and Cross-Strapping Violations
- Erroneous data sheet data
- Incorrect Decoupling
- Inadequate Interfaces: 1553, LVDS, Board-Board
- Logic Compatibility, Termination, and Un-used IC Violations
- SSO and Package Parasitics Issues
- BJT/FET Leakage/min hFE, SOA
- Power Sequencing Violations
- Layout and PDN Violations
- Filter/Bead Q Stress Violations
- Stress Items: Over-stress Conditions, Pulse resistors, IC Violations
Benefits
- Find Outages and WCCA Findings BEFORE the formal analysis process
- Help eliminate design issues before they become problems
- Save time and money by eliminating costly WCCA findings
- Highlights issues so that fixes can be applied early
- Vet bad manufacturer reference design recommendations
- Reduce Board Spins
Design Review Activities
- Prepare your organization for a WCCA and Stress analysis
- List circuit concerns along with rationale
- Recommend bench and component tests to support findings
- Develop a system test point list for use in WCCA and model correlation
- Identify design issues; both potential and actual
- Identify where worst case analyses may have findings
- Identify test and component data needed to perform a WCCA; list impediments
WCCA Review Services
AEi Systems provides independent reviews of third-party Worst Case Circuit Analyses (WCCA) to ensure compliance, accuracy, and completeness. Our reviews are frequently requested by major aerospace primes such as Lockheed Martin, who rely on AEi Systems to validate analyses performed by subcontractors. Smaller design organizations often lack the specialized skills or multidisciplinary expertise required for a compliant WCCA—while primes may not have sufficient in-house resources to review them thoroughly. AEi Systems bridges that gap.
With over 30 years of experience and authorship of key WCCA standards (including the Aerospace TOR-2012(8960)-4), AEi Systems brings unmatched insight into what government agencies and mission assurance teams expect. Our reviews identify gaps early, ensuring your deliverables withstand customer and NASA/Mil guideline scrutiny.
Activities
- Perform technical review of worst case analysis deliverables for adherence to Aerospace TOR and other guidelines.
- Assess the mathematical, modeling, and simulation accuracy and assumptions.
- Review Electrical Parts Stress Analysis (EPSA), provide comments, and support satisfactory closure of findings.
- Review Worst Case Circuit Analysis (WCCA) reporting, provide comments, and support satisfactory closure of findings.
- Provide findings, status, attend TEMs
Detailed Tasks
- Discuss and identify WCCA problem areas
- Tolerance Database (PVDB) review – review tolerances for accuracy given the defined environment (temperature range, Mission Life, and radiation levels (TID/Displacement Damage), verify tolerances are defined and used appropriately (RSS, biases, aging, manufacturing, etc.)
- Model review – review model accuracy and correlation documentation. Verify that the electrical characteristics needed by the analysis are properly modeled (i.e., present, and accurate for the operating conditions required by the particular analyses). Verify that models are appropriately toleranced.
- Methodology review – confirm that the correct methods (Sensitivity, EVA, Monte Carlo, etc.) were employed
Additional Review Tasks
- Documentation review – review the documentation for completeness and level of detail desired by the Buyer and required customer flow-downs including key elements (Compliance Matrix with margins, PVDB, etc.)
- Analysis scope review – List Command media required analysis not performed. Verify that the analyses performed are sufficient given any SDRL requirements/flow-downs and for what would customarily be performed (i.e., TOR compliant). Verify derived requirement analyses are present.
- WCCA/Stress review – review the supplied analyses for fidelity and accuracy; are the results and conclusions reasonable and acceptable.
- WCCA/Stress re-analysis – Upon mutual agreement with the Buyer, perform a deep dive into analyses, reanalyzing the function or stress condition as and where appropriate to verify accuracy and stated conclusions.
PCB Layout and Layout Review, Circuit Design Compliance
AEi Systems provides comprehensive PCB layout and review services in accordance with CID (Certified Interconnect Designer) standards to ensure reliable, manufacturable, and testable designs. Our team verifies that layouts accurately reflect schematic intent, while performing DRC checks based on IPC-2221 and IPC-2222 standards. We carefully review component placement for optimal signal routing, thermal management, and mechanical constraints, along with trace routing for correct widths, clearances, spacing, impedance control, and manufacturability.
Our services include DFM reviews to confirm compliance with fabrication and assembly requirements, as well as thermal analysis reviews to evaluate the effectiveness of heat dissipation strategies. We also assess power supply layouts for vendor compliance and PDN integrity and perform DFT reviews to ensure accessibility of test points and support for automated testing methods. Where needed, we provide specific recommendations for layout improvements to enhance overall design quality and robustness.
CID+ PCB Layout Review Activities
- Schematic-to-layout verification – confirming the layout matches design intent and critical nets are correctly implemented.
- Design rule and standards compliance – checking against IPC-2221/2222, IPC-7351, and any customer- or fab-specific rules for clearances, trace widths, creepage, and spacing.
- Component placement analysis – validating signal flow, decoupling capacitor proximity, power distribution efficiency, thermal performance, and mechanical constraints.
- Routing and signal integrity review – examining critical nets (clocks, high-speed signals, differential pairs) for impedance control, length matching, return paths, and crosstalk risk.
- Power integrity assessment – ensuring robust PDN design with adequate decoupling, ground/power plane strategy, and low-voltage rail stability.
Additional Review Areas
- Thermal management review – evaluating hot-spot placement, heat sink/thermal via effectiveness, and airflow considerations.
- DFM (Design for Manufacturing) checks – ensuring footprint accuracy, solder mask clearances, via structures, connector placement, and panelization are production-ready.
- DFT (Design for Test) checks – verifying test point accessibility, boundary scan readiness, probe clearance, and automated test compatibility.
- Reliability and risk analysis – looking for potential long-term failure points such as tight tolerances, insufficient creepage in high-voltage areas, or marginal thermal margins.
- Other checks – Controlled impedance, Minimum hole size, aspect ratio, Plating requirements, Minimum feature size, Solder mask requirements, Electrical test. Board house stackup confirmation. Connectors and cables, RF features.
Getting a Quotation
To provide you with an accurate quotation for Expert Review Services, please fill out the form and attach any relevant documentation such as:
- Circuit schematics
- PCB layouts
- Design specifications
- Previous analysis reports
Our expert review services help identify and resolve design issues before they become costly problems.
We bring decades of experience in circuit design, reliability, and best practices to bear on your circuit design, quickly and efficiently.
We provide independent validation of third-party design and analysis for compliance and accuracy.
AEi Systems is fully compliant with NIST/CUI requirements. All files are transmitted via secure means and kept strictly confidential.