From black box to blueprint: How we performed a rapid assessment of a legacy system

A deep dive into how a data-driven discovery process and advanced software intelligence unlocked a 15-year-old application, delivering clear insights and a strategic roadmap for future growth.

Organizations today face the daunting challenge of managing and modernizing complex, often decades-old, legacy applications. Understanding these systems, which can span millions of lines of code, is a significant hurdle, especially when critical knowledge is held by only a few subject matter experts (SMEs). This is the story of how our team successfully navigated such a complex technical challenge using software intelligence CAST, who we’ve been partnering with.

The challenge: Assessing a mission-critical black box

A leading agriscience organization approached us with the goal of transitioning support for their core application ecosystem to DAMO™. 

Our mission was to rapidly demystify this complex system to provide the foundational understanding required to create a clear transition plan. This meant we needed to conduct a rapid and comprehensive assessment of the system as it currently worked 

The difficulty of this task was immense:

• It was old and complicated. The system was more than 15 years old, and had evolved into a sprawling and intricate ecosystem.

• Massive in scale. The system comprised over 30 distinct components and a formidable 2.2 million lines of code.

• Siloed knowledge. The largest hurdle was SME availability. Without their deep institutional knowledge, gaining the necessary understanding of the system's workings was a significant obstacle.

The approach: Data-driven discovery with CAST

To rapidly assess the system, we employed a dual strategy, combining the deep analysis of the system using CAST components, with a comprehensive analysis of incident data. This provided a static, architectural blueprint of the application along with quality metrics and a dynamic perspective on problems that can emerge during live operations.

Application analysis using CAST

Our analysis was driven by two key components of the CAST software intelligence platform:

• CAST Gatekeeper: We primarily leveraged CAST Gatekeeper's Management and Engineering dashboards. These dashboards provided a consolidated, data-driven assessment of the application's health, quality and security. By analyzing the system against more than 1,800 metrics, we could measure its condition very precisely.

• CAST Imaging: For deeper analysis, we used CAST Imaging dashboards to gain a broad-level understanding of the application architecture, map the API inventory and identify the various frameworks in use. This gave us an immediate, interactive blueprint of the system. The future goal is to leverage this "digital SME" as live documentation to guide the support transition and assist in future application evolution.

Incident data analysis

Complementing the insights from CAST, we analyzed historical incident data. This investigation provided critical context that a source code analysis tool alone cannot. By analyzing recurring issues and tickets, we identified the problems that were actively impacting users and business operations. This step allowed us to correlate the technical weaknesses found by CAST with their real-world consequences, ensuring our final recommendations were not just technically sound, but also highly relevant to the system's most pressing operational challenges.

This dual approach allowed us to create a holistic view of the system's health. The dashboards quantified the system's challenges in concrete terms, revealing:

• Significant technical debt, measured in the effort required to fix stability issues.

• A number of critical code violations that posed risks to performance and stability.

• Benchmark scores for key quality attributes based on ISO 5055 standards, including the application's overall total quality index (TQI) and specific measures for robustness, security and efficiency.

The results: A clear path forward

By combining the power of CAST with our engineering expertise, we completed the comprehensive system assessment in just one month. This rapid analysis helped deliver several key things:

• Accelerated system understanding. The visual blueprints and detailed metrics provided unprecedented clarity into the 15-year-old application.

• Pinpointed technical risks. We delivered a clear identification of technical risk areas, including specific software and security violations and areas of high technical debt.

• Improved onboarding readiness. The structured documentation and clear insights significantly improved the onboarding readiness for the incoming Digital Application Management and Operations (DAMO™) team.

• A foundation for strategic planning: The assessment provided a solid, data-driven foundation to define the transition plan and its scope.

   

Based on these findings, we delivered a set of concrete, actionable recommendations to guide the application's future.

Ultimately, what seemed like an insurmountable assessment challenge was transformed into a strategically defined initiative. The organization now has a clear, evidence-based roadmap for the evolution and long-term health of its critical application ecosystem, ensuring its stability and adaptability for years to come.