Requirements Engineering - tj0vtj0v/KI-B-4-Software_Engineering GitHub Wiki

The requirements defined in this document address the key functionalities of the microwave system, focusing on:

  • Door-open interruption
  • Overheating prevention
  • Power control
  • Control of radiation distribution
  • Interior lighting

These functionalities represent essential subsystems necessary for implementing a safe and effective defrosting program. Each has been carefully analyzed and translated into detailed functional and non-functional requirements, organized into safety-related and technical aspects. This structured approach ensures thorough coverage of both safety-critical behavior and core operational logic throughout the system design.

1. Functional Requirements

1.1 Safety-Related Functional Requirements

  • REQ-1.1.1 Door-Open Interlock
    If the door is open or unlocked, high-voltage generation and all rotating parts are disabled, and user inputs are blocked.

  • REQ-1.1.2 Overheat Shutdown
    If the temperature exceeds a critical threshold, the magnetron power is cut, all rotations stop, and an alert sound is emitted.

  • REQ-1.1.3 Interior Lighting Safety Interlock
    The interior light activates during program operation or when the door is open, and turns off otherwise.

  • REQ-1.1.4 Alert Control
    The alert is engaged when immediate attention or action is necessary.

  • REQ-1.1.5 Sliding-Window Power Regulation
    Power is regulated to ensure the magnetron duty cycle remains under 80% within each one-minute window.

1.2 Operational and Technical Functional Requirements

  • REQ-1.2.1 Main Controller State Machine
    The main controller manages transitions between Idle, Setup, Running, Paused, Completed, and Error states, handling safety interlocks, faults, and user commands.

  • REQ-1.2.2 Emergency Protocol
    An emergency handler manages critical failures by safely shutting down operations and notifying the user.

  • REQ-1.2.3 Sensor Fault Handling and Recovery
    The system detects sensor faults and initiates predefined recovery or safe-failure procedures to maintain safe operation.

  • REQ-1.2.4 Sensor Management
    Sensor readings are polled and debounced at a minimum rate of 10 Hz, with noise filtering applied and faults reported to the main controller.

  • REQ-1.2.5 Cooling Fan Control
    The cooling fan activates when the magnetron is operating or the temperature exceeds 50 °C, adjusting speed based on temperature changes.

  • REQ-1.2.6 Magnetron Power Control
    The magnetron power shall be controlled smoothly across adjustable power levels, including an off-state during standby.

  • REQ-1.2.7 Turntable Rotation Control
    The turntable rotates at a variable speed between 0 and 5 rpm.

  • REQ-1.2.8 Reflector Arm Rotation
    The reflector arm oscillates at a fixed frequency to ensure uniform heating.

  • REQ-1.2.9 User Interface Display
    The interface shows current time, power level, program name, and remaining cooking time.

  • REQ-1.2.10 User Inputs
    Users can configure power, cooking time, and select or store custom programs.

  • REQ-1.2.11 Program Execution Controls
    Users can start, pause, abort, or stop cooking programs.

  • REQ-1.2.12 Door Release Mechanism
    The door can only be mechanically released after program completion or abortion.

  • REQ-1.2.13 Input Watchdog
    The watchdog reactivates the main loop if interaction is detected.

  • REQ-1.2.14 Program Storage
    Custom and preset cooking programs are stored in non-volatile memory.

  • REQ-1.2.15 Event Logging
    Critical events and faults are logged for maintenance and diagnostics.

2. Non-Functional Requirements

2.1 Safety-Related Non-Functional Requirements

  • REQ-2.1.1 Test Coverage
    At least 90% of safety-critical code paths, including boundary cases, must be covered by unit and integration tests.

  • REQ-2.1.2 Documentation and Traceability
    A safety manual detailing hazards, failure modes, and mitigation strategies must be maintained. All requirements shall be mapped to corresponding implementation artifacts and tests, with an up-to-date requirements traceability matrix managed under a change-control process.

2.2 Development-Related Non-Functional Requirements

  • REQ-2.2.1 Performance
    The UI must respond within 100 ms; sensor jitter should remain under 5 ms; safety interlocks must react within 50 ms. Sensor data processing latency must be minimized to ensure real-time responsiveness.

  • REQ-2.2.2 Maintainability
    Code must adhere to quality standards with automated checks and limited function complexity.

  • REQ-2.2.3 Modularity
    Software components such as sensor drivers, actuator drivers, user interface, and safety logic must be modularized and separated via a hardware abstraction layer.

  • REQ-2.2.4 Reusability
    If possible already existing modules shall be used.

  • REQ-2.2.5 Agile Iteration Support
    Development follows sprint cycles with backlog refinement, sprint reviews, and delivery of vertical slices.