Honeywell CP-6 Modernization: Salvaging Legacy Aerospace Workflows for Web

Honeywell CP-6 (Control Program-6) systems are the silent engines of the aerospace and defense sectors, but they are increasingly becoming ticking time bombs of technical debt. These mainframe environments, while historically robust, lack the interoperability required for modern cloud-native architectures. The tribal knowledge required to maintain them is retiring, and the cost of a "rip and replace" strategy is often prohibitive. According to Replay’s analysis, 70% of legacy rewrites fail or exceed their timeline because the original logic is buried in undocumented terminal workflows rather than clean source code.

For engineering leaders, the challenge isn't just moving data; it’s honeywell modernization salvaging legacy workflows that have been refined over forty years. When you lose the interface, you lose the business process.

TL;DR: Modernizing Honeywell CP-6 doesn't require a 24-month manual rewrite. By using Replay, enterprises can record existing terminal workflows and automatically generate documented React components and Design Systems. This approach reduces the modernization timeline from years to weeks, saving 70% in labor costs while preserving mission-critical aerospace logic.

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The High Stakes of Honeywell Modernization Salvaging Legacy Systems#

The aerospace industry operates on a $3.6 trillion global technical debt mountain. In CP-6 environments, the "source of truth" isn't a Git repository—it's the screen. These systems often handle complex telemetry data, supply chain logistics, and maintenance scheduling that modern ERPs struggle to replicate without significant customization.

Industry experts recommend a "Visual-First" approach to modernization. Because 67% of legacy systems lack documentation, attempting to read the underlying PL/6 or Fortran code is a recipe for disaster. Instead, focus on the user’s workflow.

Visual Reverse Engineering is the process of capturing real user interactions with a legacy system and using AI to translate those visual patterns into modern code structures.

By focusing on honeywell modernization salvaging legacy assets, organizations can bypass the "Black Box" problem. Instead of guessing what a specific function key does, you record the expert user performing the task and let Replay map the state transitions.

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Why Manual Rewrites Fail in Aerospace#

The traditional approach to aerospace modernization involves hiring a fleet of consultants to document every screen manually. This process typically takes 40 hours per screen. For a system with 500+ screens, you are looking at an 18-month average enterprise rewrite timeline before a single line of production-ready React is even written.

Comparison: Manual vs. Replay-Assisted Modernization#

As shown in the table, honeywell modernization salvaging legacy workflows via automation provides a 10x speed advantage. This is critical in regulated environments where every change must be audited and verified against the original system's behavior.

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Step-by-Step: Converting CP-6 Workflows to React#

To successfully execute a honeywell modernization salvaging legacy project, you need a pipeline that moves from pixel to component. Here is the architectural blueprint for moving Honeywell CP-6 terminal screens into a modern React-based Design System.

Step 1: Record the Workflow (The "Flows" Phase)#

The first step is recording the "Golden Path" of your aerospace application. Whether it’s a parts procurement screen or a flight-line maintenance log, you capture the session using Replay’s recording tools.

Video-to-code is the process of using computer vision and Large Language Models (LLMs) to identify UI patterns (buttons, inputs, data tables) within a video stream and outputting functional code.

Step 2: Extracting the Component Library#

Once the video is processed, Replay identifies recurring UI elements. In CP-6, this might be specific grid layouts or command-line prompts. These are converted into a standardized Design System. This ensures that your new web-based UI remains consistent even if multiple teams are working on different modules.

For more on building these libraries, check out our guide on Building Scalable Design Systems from Legacy UIs.

Step 3: Mapping State and Logic#

The most difficult part of honeywell modernization salvaging legacy systems is mapping the "F-key" logic to modern event handlers. Below is an example of how a legacy Honeywell terminal input might be refactored into a modern TypeScript React component using Replay's generated patterns.

typescript
// Generated by Replay AI Automation Suite
// Source: Honeywell CP-6 Maintenance Module (Screen 402)

import React, { useState, useEffect } from 'react';
import { Button, Input, Table, Alert } from '@/components/ui-library';

interface PartRecord {
  partId: string;
  status: 'active' | 'deprecated';
  lastService: string;
}

export const MaintenanceWorkflow: React.FC = () => {
  const [inputVal, setInputVal] = useState<string>('');
  const [record, setRecord] = useState<PartRecord | null>(null);

  // Mapping Legacy F3 (Search) to Modern Action
  const handleLegacySearch = async (id: string) => {
    try {
      const data = await fetchPartData(id);
      setRecord(data);
    } catch (err) {
      console.error("Legacy Protocol Error", err);
    }
  };

  return (
    <div className="p-6 bg-slate-50 rounded-lg shadow-md">
      <h2 className="text-xl font-bold mb-4">Part Tracking: CP-6 Migration</h2>
      <div className="flex gap-4 mb-6">
        <Input 
          placeholder="Enter Part ID (Legacy Format)"
          value={inputVal}
          onChange={(e) => setInputVal(e.target.value)}
        />
        <Button onClick={() => handleLegacySearch(inputVal)}>
          Search (F3)
        </Button>
      </div>
      
      {record && (
        <Table data={[record]} columns={['partId', 'status', 'lastService']} />
      )}
    </div>
  );
};

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Addressing the "Black Box" with AI Automation#

One of the primary fears in honeywell modernization salvaging legacy aerospace software is the "Black Box" effect—where the original developers are gone, and the source code is unreadable.

Replay addresses this through its AI Automation Suite. By analyzing the visual state transitions in the recording, the AI can infer the underlying data structures. For instance, if a user enters a tail number and the screen populates a table, Replay identifies that relationship and builds the corresponding React props and state hooks automatically.

According to Replay's analysis, this visual-first approach identifies 30% more edge cases than manual code audits because it captures how users actually use the system, rather than how the code was intended to work 30 years ago.

Developing a Modern Data Layer#

When salvaging legacy systems, you aren't just changing the UI; you are often building a middleware layer to communicate with the mainframe via terminal emulation or modern APIs. Your React components need to handle these asynchronous streams gracefully.

typescript
// Example of a custom hook for legacy data streaming
// Integrated with Replay's generated Blueprints

import { useQuery } from '@tanstack/react-query';

export function useHoneywellData(endpoint: string, queryKey: string) {
  return useQuery({
    queryKey: [queryKey],
    queryFn: async () => {
      const response = await fetch(`/api/v1/legacy-bridge/${endpoint}`);
      if (!response.ok) {
        throw new Error('Network response was not ok');
      }
      return response.json();
    },
    // Ensure we don't overwhelm the legacy mainframe
    staleTime: 1000 * 60 * 5, 
    retry: 2,
  });
}

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Security and Compliance in Regulated Modernization#

Aerospace and Defense projects require more than just "working" code; they require SOC2, HIPAA-level, and often On-Premise security. Honeywell modernization salvaging legacy systems cannot happen in a public cloud if the data is sensitive.

Replay is built for these environments. With On-Premise deployment options and SOC2 compliance, the platform ensures that your recordings and generated code never leave your secure perimeter. This is a significant advantage over generic AI coding assistants that require sending data to external LLMs.

For more on secure modernization, read our article on Modernizing in Regulated Environments.

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Implementation Strategy: The 4-Week Pilot#

Instead of a multi-year roadmap, we recommend a 4-week pilot focused on a single high-value workflow. This proves the efficacy of honeywell modernization salvaging legacy assets without over-committing resources.

1. •Week 1: Capture. Identify the top 10 most critical screens in the CP-6 environment. Use Replay to record expert users performing these tasks.
2. •Week 2: Extraction. Use the Replay Library to generate the initial React components and Design System.
3. •Week 3: Refinement. Use the Replay Blueprints (Editor) to tweak the generated code, add modern validation, and connect to your new data layer.
4. •Week 4: Deployment. Deploy a functional web-based version of the legacy workflow for user acceptance testing (UAT).

This rapid iteration cycle is how you beat the 70% failure rate associated with legacy rewrites.

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Frequently Asked Questions#

How does Replay handle terminal-based "green screens" from Honeywell CP-6?#

Replay's Visual Reverse Engineering doesn't care about the underlying tech stack. It treats the terminal output as a visual interface. By recording the screen, Replay identifies characters, grids, and input fields, converting them into a modern React

or component while maintaining the original workflow logic.

Is the generated React code maintainable?#

Yes. Unlike "low-code" platforms that output "spaghetti code," Replay generates standard TypeScript/React code that follows your organization's specific coding standards. It integrates with your existing CI/CD pipelines and Design Systems.

Can we use Replay for on-premise Honeywell systems that aren't connected to the internet?#

Absolutely. Replay offers an On-Premise version specifically designed for aerospace, government, and manufacturing sectors. You can run the entire extraction and generation engine within your own secure network to ensure data sovereignty.

What happens if the legacy system has no documentation?#

This is where Replay excels. Since the platform uses visual recording as the source of truth, it creates its own documentation. Every generated component is linked back to the original screen recording, providing a clear "audit trail" of why the code was built the way it was.

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The Future of Aerospace UI#

The era of manual rewrites is ending. As the global technical debt reaches $3.6 trillion, the only way to keep pace with digital transformation is through automation. By focusing on honeywell modernization salvaging legacy workflows, aerospace companies can transition to the web without losing the decades of intelligence baked into their CP-6 systems.

The choice is simple: Spend 40 hours per screen doing it manually, or 4 hours per screen using Visual Reverse Engineering.

Ready to modernize without rewriting? Book a pilot with Replay