Is this how to get a KPI for NFRs?

I am learning system design, NFRs, UX case studies, and Security Assurance Programs like OWASP SAMM for example. I have been trying to understand if this how you get a KPI for NFRs, and I have been trying to figure out is if I use Business Impact Analysis, Service Impact Analysis, Risk Analysis?

1. Where BIA, SIA, and RA Fit in Your Framework These three risk-focused exercises act as a filter. They take your Business Inputs (1 Billion users) and ask: "What is the financial, operational, and technical impact if this system fails or slows down?"┌─────────────────────────────────────────┐
│       2. Business Input / Goals         │
│  (1B Users, 1 Post/Day, 10 Likes/Day)   │
└────────────────────┬────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────┐
│       BIA, SIA, & Risk Analysis         │ <── Calculates financial loss, user churn,
│  (How bad is a failure or 2-sec delay?) │     and system vulnerabilities.
└────────────────────┬────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────┐
│    3 & 4. Traffic Estimates & KPIs      │ <── Sets the maximum boundaries the
│ (10k/100k QPS, Throughput, p95 Latency) │     system must handle to avoid risk.
└─────────────────────────────────────────┘
Business Impact Analysis (BIA): Quantifies the financial and operational loss if the system degrades. For example: "If search latency exceeds 1 second, user engagement drops by 20%, costing the company $500,000 per day in lost ad revenue.

"Service Impact Analysis (SIA): Determines which microservices will break downstream. For example: "If the 'Like' database slows down under a 100k QPS spike, it will cascade and crash the Newsfeed service.

"Risk Analysis (RA): Identifies the vulnerabilities and threats to your capacity. For example: "There is a high risk of localized traffic spikes during major global events (e.g., the World Cup), which could double our peak traffic overnight."

2. How to Get the Traffic Estimates (Step 3)You derive the Traffic Estimates by combining your Business Inputs with your Risk Analysis (RA) safety factors. You never build a system exactly for the average traffic; you build it to survive the peak traffic calculated during Risk Analysis. The Formula: Calculate the Average Baseline:$$\frac{\text{1 Billion Posts}}{\text{100k seconds}} = 10,000 \text{ posts/sec (Average Load)}$$Apply the Risk Analysis Peak Factor: Your Risk Analysis tells you that traffic is never perfectly flat. Peak hours (like 8:00 PM) or breaking news events usually cause a $3\times$ to $5\times$ spike above the average baseline. The Final Traffic Estimate:$$10,000 \text{ Average QPS} \times 3 (\text{Risk Spike Factor}) = \mathbf{30,000 \text{ Peak Ingress QPS}}$$By using the math this way, your Traffic Estimate accounts for real-world risks, ensuring you provision enough servers to handle the maximum possible stress.

3. How to Get the Technical KPIs (Step 4)Your Technical KPIs are derived directly from the thresholds discovered during the BIA and SIA. The business impact tells you exactly what technical thresholds you need to measure to ensure the platform remains healthy. To get the specific KPIs, you map the BIA/SIA risks to automated technical metrics: Example 1: Deriving the Read KPI from BIA The BIA Finding: A delay over $1,000\text{ms}$ causes rapid user churn and loss of ad revenue. The Resulting Technical KPI: Search_Read_Latency_p99. You monitor the 99th percentile specifically because the BIA proved that letting even 1% of your users experience 1-second delays damages the business bottom line. Example 2: Deriving the Write KPI from SIAT he SIA Finding: If the database takes longer than $200\text{ms}$ to process a "Like" write request, the API Gateway's connection pool will saturate, causing a complete system outage. The Resulting Technical KPI: Like_Write_Throughput_Capacity and Database_Connection_Queue_Length.The Complete Enterprise Framework View When we inject BIA, SIA, and RA into your exact layout, the complete architectural picture locks into place: Framework Layer Description Example from Our System Driven/Informed By

1. Business KRA High-level strategic goal. User Growth & High Platform Engagement. Corporate Vision & Market Scan
2. Business Input Expected product metrics.1B users producing 1 post/day and 10 likes/day. Product Management & Growth Targets Analysis Intercept BIA, SIA, and Risk Analysis Assess the risk of 100k QPS load spikes and the financial impact of latency. Risk Assessment Frameworks
3. Traffic Estimate Back-of-the-envelope math + Risk safety factors.10k Average QPS (30k Peak QPS), 3.6 PB total storage. Business Inputs + Risk Spike Factors
4. Technical KPI Technical metrics monitored to prevent business impact. Write_Throughput_Capacity and Read_Response_Latency_p99.SIA Connection Limits & BIA Churn Thresholds
5. NFR Target The hard architectural constraint. Search results must render in $< 500\text{ms}$ at a peak of 30k QPS. Human Perception Limits & Revenue Protection