The Pascal Paradox: Why Industrial HMIs are the Next Frontier for React

The $3.6 trillion technical debt crisis isn't just about old banking COBOL; it’s hidden in the flickering CRTs of factory floors and manufacturing plants running Pascal-based industrial control systems. These systems, often built in Delphi or Lazarus, manage multimillion-dollar assembly lines with logic that hasn't been touched since the late 90s. When these interfaces fail, production stops. When the last engineer who understands the original Pascal source code retires, the risk becomes existential.

Modernizing these environments is no longer a luxury; it is a requirement for Industry 4.0. However, the traditional path—a manual rewrite—is a minefield. With an 18-month average enterprise rewrite timeline and a 70% failure rate for legacy migrations, organizations need a more surgical approach. This is where pascal industrial control transforming into React-based architectures becomes the primary objective for the modern enterprise architect.

By leveraging Replay, organizations are moving away from manual code archeology. Instead of spending 40 hours per screen trying to decipher undocumented Delphi event handlers, teams are using Visual Reverse Engineering to convert recorded workflows directly into clean, documented React components in a fraction of the time.

TL;DR: Pascal-based industrial UIs are brittle and lack documentation, creating massive technical debt. Manual rewrites take 18+ months and often fail. Replay enables pascal industrial control transforming by recording legacy workflows and automatically generating React components, Design Systems, and Architecture Flows. This reduces modernization time by 70%, turning a 40-hour manual screen conversion into a 4-hour automated process.

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The Fragility of Pascal Industrial Control Systems#

Pascal, specifically in its Object Pascal and Delphi incarnations, was the gold standard for industrial Human-Machine Interfaces (HMIs) due to its strong typing and direct hardware access. But what was an asset in 1998 is a liability in 2024. These systems are often "black boxes." According to Replay's analysis, 67% of legacy systems lack any form of up-to-date documentation.

Video-to-code is the process of capturing the visual state and user interactions of a legacy application through video recording and using AI-driven spatial analysis to generate functional frontend code.

When we talk about pascal industrial control transforming, we aren't just talking about changing a UI. We are talking about decoupling critical hardware logic from the presentation layer. In a typical Delphi industrial app, the business logic (e.g., "if temperature > 500, kill the engine") is often tightly coupled with the UI button click event.

The Cost of Manual Modernization#

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Pascal Industrial Control Transforming: The Technical Bridge#

The biggest challenge in pascal industrial control transforming is the transition from imperative, event-driven Pascal to declarative, state-driven React. In Pascal, you might find a deeply nested set of

blocks inside a procedure.

Industry experts recommend a "Visual-First" approach to avoid the 70% failure rate of manual rewrites. Instead of reading the Pascal source (which may be lost or obfuscated), Replay records the application in action. It sees the buttons, the gauges, the data grids, and the modal alerts, and maps their behavior to modern React hooks and components.

Example: Legacy Pascal Logic vs. Modern React#

Consider a simplified Pascal procedure for a pressure valve controller:

pascal
// Legacy Delphi/Pascal Industrial Control Logic
procedure TMainForm.btnOpenValveClick(Sender: TObject);
begin
  if (CurrentPressure < MaxSafePressure) then
  begin
    ValveStatus := vsOpen;
    ShapeValveIndicator.Brush.Color := clGreen;
    lblStatus.Caption := 'Valve Open';
    LogActivity('User opened valve manually');
  end
  else
  begin
    ShowMessage('Error: Pressure too high!');
    LogActivity('Valve open blocked: High Pressure');
  end;
end;

In this legacy snippet, the UI state (

, ) is mixed directly with the safety logic. When Replay ingests a recording of this interaction, it identifies the "Valve" as a component and the "Pressure" as a state variable, generating a clean React equivalent:

typescript
// Modernized React Component via Replay
import React, { useState } from 'react';
import { useIndustrialLogic } from './hooks/useIndustrialLogic';
import { Alert, Button, StatusIndicator } from './components/ui';

export const ValveController: React.FC<{ maxPressure: number }> = ({ maxPressure }) => {
  const { pressure, openValve, status, error } = useIndustrialLogic();

  return (
    <div className="p-6 bg-slate-900 rounded-lg">
      <StatusIndicator 
        active={status === 'OPEN'} 
        color={status === 'OPEN' ? 'green' : 'red'} 
        label={`Status: ${status}`}
      />
      
      <div className="mt-4">
        <Button 
          onClick={openValve}
          disabled={pressure >= maxPressure}
          variant="primary"
        >
          Open Valve
        </Button>
      </div>

      {error && <Alert type="error" message={error} />}
    </div>
  );
};

By separating the concerns, the pascal industrial control transforming process ensures that the new UI is maintainable, testable, and ready for integration with modern IoT backends via MQTT or WebSockets.

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The Replay Workflow: From Recording to React#

The Replay platform doesn't just "guess" what the code should look like. It uses a structured pipeline designed for enterprise-grade modernization. For a deep dive into how this fits into broader strategies, see our guide on Legacy Modernization Strategies.

1. The Capture (Video Recording)#

A subject matter expert (SME) records the legacy Pascal application. They walk through every "Flow"—from login to emergency shutdown. Replay's AI analyzes the video frames to identify UI patterns, layout structures, and interactive elements.

2. The Library (Design System)#

Replay automatically extracts the visual DNA of the industrial system. It identifies consistent colors, typography, and component shapes. These are organized into a Design System, ensuring that the new React app feels familiar to operators who have used the Pascal system for decades.

3. The Flows (Architecture Mapping)#

This is where the pascal industrial control transforming magic happens. Replay maps the user journey. If clicking "Button A" leads to "Screen B," Replay documents this as a functional flow. This replaces the 67% of missing documentation with a live, visual map of the application's architecture.

4. The Blueprints (React Generation)#

Finally, the platform generates the code. This isn't "spaghetti code." It's production-ready TypeScript and React, utilizing modern best practices like Tailwind CSS and shadcn/ui-inspired component structures.

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Security and Compliance in Industrial Modernization#

Industrial environments—especially in Healthcare, Energy, and Government—cannot compromise on security. Moving from a standalone Pascal

to a web-based React application introduces new surface areas.

Replay is built for these regulated environments. The platform is SOC2 compliant and HIPAA-ready. For facilities where data cannot leave the local network (like nuclear power plants or secure manufacturing floors), Replay offers On-Premise deployment. This ensures that the pascal industrial control transforming process happens entirely within the organization's firewall.

Visual Reverse Engineering is the methodology of reconstructing an application's functional logic and design by analyzing its visual output and user interaction patterns rather than its underlying source code.

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Why Pascal Industrial Control Transforming is Urgent#

The global technical debt of $3.6 trillion is a ticking time bomb. In the context of industrial controls, this debt manifests as:

• •Hardware Lock-in: Legacy Pascal apps often require specific Windows versions (like XP or 7) that are no longer supported.
• •Talent Scarcity: Finding a developer who can debug a complex Delphi 5 application is becoming impossible.
• •Inflexibility: You cannot easily add modern features like mobile monitoring, AI-driven predictive maintenance, or cloud-based analytics to a legacy Pascal HMI.

By using Replay, companies are turning these liabilities into assets. They are taking the proven, battle-tested logic of their Pascal systems and wrapping it in a modern React shell that can run on any device, anywhere.

According to Replay's analysis...#

Enterprises that attempt to manually rewrite their industrial UIs spend 40% of their budget just on "discovery"—trying to understand what the old system actually does. Replay reduces discovery time to near zero by providing an instant visual inventory of every screen and interaction.

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Case Study: Manufacturing Floor Modernization#

A global semiconductor manufacturer had a critical etch-control system written in Turbo Pascal. The UI was a text-heavy, keyboard-only interface. The goal was pascal industrial control transforming into a touch-enabled React tablet interface for floor supervisors.

• •The Challenge: No source code was available for the original Pascal logic.
• •The Replay Solution: The team recorded 12 hours of operator workflows. Replay identified 45 unique screens and 120 interactive components.
• •The Result: Within 3 weeks, the team had a functional React prototype that matched the original logic with 100% accuracy. The full production rollout was completed in 3 months—a task previously estimated at 18 months.

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Frequently Asked Questions#

How does Replay handle Pascal logic that isn't visible on screen?#

While Replay excels at capturing visual state and UI-driven logic, "invisible" backend logic (like direct PLC memory writes) is documented as "System Actions" in the Flows view. This allows developers to see exactly where a hardware call needs to be integrated into the new React architecture.

Can we export the generated React code to our own Git repository?#

Yes. Replay generates standard, clean TypeScript and React code that is fully portable. There is no vendor lock-in. Once the pascal industrial control transforming process is complete, the code is yours to manage, deploy, and extend.

Does Replay work with old Delphi versions like Delphi 7 or 2006?#

Absolutely. Because Replay uses Visual Reverse Engineering, it is agnostic to the version of Pascal or Delphi used. As long as the application can run on a screen and be recorded, Replay can transform it.

How does this affect the 70% failure rate of legacy rewrites?#

The 70% failure rate is primarily caused by "scope creep" and "lost logic"—forgetting how the old system worked. Replay eliminates these risks by using the legacy system as the "source of truth," ensuring the new React app is a functional twin of the original.

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The Future of Industrial Interfaces#

The era of the "monolithic Pascal EXE" is ending. The future belongs to modular, component-based architectures that can evolve as fast as the hardware they control. Pascal industrial control transforming is the bridge to that future.

By automating the most tedious parts of the modernization journey—the documentation, the component design, and the basic state mapping—Replay allows enterprise architects to focus on what matters: innovation and safety.

Ready to modernize without rewriting? Book a pilot with Replay and see how we can turn your legacy Pascal systems into a modern React library in weeks, not years.