From 85024f86702816313f0e3d8517c0b1ea27bdb911 Mon Sep 17 00:00:00 2001
From: Kai Chappell <git@kschappell.com>
Date: Mon, 10 Feb 2025 12:06:22 +0000
Subject: [PATCH] Restructure package for domain-driven design

Reorganise package structure to improve separation of concerns:
- instruments/ - SCPI, transport, drivers, interfaces, factory
- simulation/ - physics engine, virtual instruments, server
- framework/ - test runner, logger, limits, context
- tests/ - thermal/, electrical/ (DVT test implementations)
- data/ - repository, models
- reporting/ - generator, templates
- app/ - CLI, config, dashboard

This structure enables:
- Reusable instruments package for other test suites
- Clear separation of simulation (dev) vs production code
- Domain-focused package organisation

Updated documentation to reflect new paths.
---
 docs/02_technical_specification.md            | 443 +++++++-----------
 docs/04_development_plan.md                   | 155 +++---
 pyproject.toml                                |   6 +-
 src/py_dvt_ate/app/__init__.py                |   5 +
 src/py_dvt_ate/{cli/main.py => app/cli.py}    |   0
 src/py_dvt_ate/app/dashboard/__init__.py      |   5 +
 src/py_dvt_ate/cli/__init__.py                |   1 -
 src/py_dvt_ate/config/__init__.py             |   1 -
 src/py_dvt_ate/dashboard/__init__.py          |   1 -
 src/py_dvt_ate/drivers/__init__.py            |   1 -
 src/py_dvt_ate/executive/__init__.py          |   1 -
 src/py_dvt_ate/framework/__init__.py          |   5 +
 src/py_dvt_ate/hal/__init__.py                |   1 -
 src/py_dvt_ate/hal/impl/__init__.py           |   1 -
 src/py_dvt_ate/instruments/__init__.py        |  10 +-
 .../instruments/drivers/__init__.py           |   5 +
 .../instruments/transport/__init__.py         |   6 +
 src/py_dvt_ate/physics/__init__.py            |   1 -
 src/py_dvt_ate/physics/dut/__init__.py        |   1 -
 src/py_dvt_ate/reporting/__init__.py          |   5 +
 src/py_dvt_ate/server/__init__.py             |   1 -
 src/py_dvt_ate/simulation/__init__.py         |   5 +
 src/py_dvt_ate/simulation/physics/__init__.py |   5 +
 .../simulation/physics/models/__init__.py     |   5 +
 src/py_dvt_ate/simulation/virtual/__init__.py |   5 +
 src/py_dvt_ate/tests/__init__.py              |   7 +-
 src/py_dvt_ate/tests/electrical/__init__.py   |   5 +
 src/py_dvt_ate/tests/thermal/__init__.py      |   5 +
 src/py_dvt_ate/transport/__init__.py          |   1 -
 29 files changed, 332 insertions(+), 361 deletions(-)
 create mode 100644 src/py_dvt_ate/app/__init__.py
 rename src/py_dvt_ate/{cli/main.py => app/cli.py} (100%)
 create mode 100644 src/py_dvt_ate/app/dashboard/__init__.py
 delete mode 100644 src/py_dvt_ate/cli/__init__.py
 delete mode 100644 src/py_dvt_ate/config/__init__.py
 delete mode 100644 src/py_dvt_ate/dashboard/__init__.py
 delete mode 100644 src/py_dvt_ate/drivers/__init__.py
 delete mode 100644 src/py_dvt_ate/executive/__init__.py
 create mode 100644 src/py_dvt_ate/framework/__init__.py
 delete mode 100644 src/py_dvt_ate/hal/__init__.py
 delete mode 100644 src/py_dvt_ate/hal/impl/__init__.py
 create mode 100644 src/py_dvt_ate/instruments/drivers/__init__.py
 create mode 100644 src/py_dvt_ate/instruments/transport/__init__.py
 delete mode 100644 src/py_dvt_ate/physics/__init__.py
 delete mode 100644 src/py_dvt_ate/physics/dut/__init__.py
 create mode 100644 src/py_dvt_ate/reporting/__init__.py
 delete mode 100644 src/py_dvt_ate/server/__init__.py
 create mode 100644 src/py_dvt_ate/simulation/__init__.py
 create mode 100644 src/py_dvt_ate/simulation/physics/__init__.py
 create mode 100644 src/py_dvt_ate/simulation/physics/models/__init__.py
 create mode 100644 src/py_dvt_ate/simulation/virtual/__init__.py
 create mode 100644 src/py_dvt_ate/tests/electrical/__init__.py
 create mode 100644 src/py_dvt_ate/tests/thermal/__init__.py
 delete mode 100644 src/py_dvt_ate/transport/__init__.py

diff --git a/docs/02_technical_specification.md b/docs/02_technical_specification.md
index e96abef..a85556f 100644
--- a/docs/02_technical_specification.md
+++ b/docs/02_technical_specification.md
@@ -214,7 +214,7 @@ For **why** decisions were made, see `03_architecture_decisions.md`.
 ### 2.1 Directory Layout
 
 ```
-thermaulate/
+py_dvt_ate/
 ├── pyproject.toml              # Project metadata and dependencies
 ├── README.md                   # Project overview and quick start
 ├── CHANGELOG.md                # Version history
@@ -222,205 +222,163 @@ thermaulate/
 ├── docs/
 │   ├── 01_requirements.md              # Business Requirements
 │   ├── 02_technical_specification.md   # Technical Design (this doc)
-│   └── 03_architecture_decisions.md    # Architecture Decisions
+│   ├── 03_architecture_decisions.md    # Architecture Decisions
+│   └── 04_development_plan.md          # Sprint breakdown
 │
-├── src/
-│   └── thermaulate/
+├── src/py_dvt_ate/
+│   ├── __init__.py                     # Package version
+│   ├── py.typed                        # PEP 561 marker
+│   │
+│   ├── instruments/                    # INSTRUMENT CONTROL (reusable)
+│   │   ├── __init__.py
+│   │   ├── interfaces.py               # IThermalChamber, IPowerSupply, IMultimeter
+│   │   ├── scpi.py                     # SCPI parser (shared protocol)
+│   │   ├── factory.py                  # Creates instrument sets from config
+│   │   ├── transport/                  # Connection layer
+│   │   │   ├── __init__.py
+│   │   │   ├── base.py                 # Transport protocol
+│   │   │   ├── tcp.py                  # TCP socket transport
+│   │   │   └── visa.py                 # PyVISA transport (future)
+│   │   └── drivers/                    # SCPI driver implementations
+│   │       ├── __init__.py
+│   │       ├── base.py                 # Base driver
+│   │       ├── chamber.py              # Thermal chamber driver
+│   │       ├── power_supply.py         # PSU driver
+│   │       └── multimeter.py           # DMM driver
+│   │
+│   ├── simulation/                     # PHYSICS SIMULATION (dev/test only)
+│   │   ├── __init__.py
+│   │   ├── server.py                   # TCP server hosting virtual instruments
+│   │   ├── physics/                    # Physics engine
+│   │   │   ├── __init__.py
+│   │   │   ├── engine.py               # Main simulation loop
+│   │   │   ├── thermal.py              # Thermal calculations
+│   │   │   └── models/                 # DUT models
+│   │   │       ├── __init__.py
+│   │   │       ├── base.py             # DUT protocol
+│   │   │       └── ldo.py              # LDO model
+│   │   └── virtual/                    # Virtual instrument implementations
+│   │       ├── __init__.py
+│   │       ├── base.py                 # Base virtual instrument
+│   │       ├── chamber.py              # Virtual thermal chamber
+│   │       ├── power_supply.py         # Virtual PSU
+│   │       └── multimeter.py           # Virtual DMM
+│   │
+│   ├── framework/                      # TEST FRAMEWORK (reusable)
+│   │   ├── __init__.py
+│   │   ├── runner.py                   # Test sequencer
+│   │   ├── context.py                  # Runtime context
+│   │   ├── logger.py                   # Measurement logging
+│   │   ├── limits.py                   # Pass/fail evaluation
+│   │   └── models.py                   # Framework models
+│   │
+│   ├── tests/                          # DVT TEST IMPLEMENTATIONS
+│   │   ├── __init__.py
+│   │   ├── base.py                     # Base test class
+│   │   ├── thermal/                    # Thermal characterisation tests
+│   │   │   ├── __init__.py
+│   │   │   └── tempco.py               # Temperature coefficient test
+│   │   └── electrical/                 # Electrical characterisation tests
+│   │       ├── __init__.py
+│   │       └── load_regulation.py      # Load regulation test
+│   │
+│   ├── data/                           # DATA PERSISTENCE (shared)
+│   │   ├── __init__.py
+│   │   ├── repository.py               # Data access layer
+│   │   └── models.py                   # Data models
+│   │
+│   ├── reporting/                      # REPORT GENERATION (standalone)
+│   │   ├── __init__.py
+│   │   ├── generator.py                # Report generator
+│   │   └── templates/                  # Report templates
+│   │
+│   └── app/                            # APPLICATION ENTRY POINTS
 │       ├── __init__.py
-│       ├── py.typed                     # PEP 561 marker
-│       │
-│       ├── physics/                     # Physics simulation engine
-│       │   ├── __init__.py
-│       │   ├── engine.py                # Main physics loop
-│       │   ├── thermal.py               # Thermal domain model
-│       │   ├── electrical.py            # Electrical domain model
-│       │   └── dut/
-│       │       ├── __init__.py
-│       │       ├── base.py              # DUT base class
-│       │       └── ldo.py               # LDO voltage regulator model
-│       │
-│       ├── instruments/                 # Virtual instrument implementations
-│       │   ├── __init__.py
-│       │   ├── base.py                  # Instrument base class
-│       │   ├── scpi_parser.py           # SCPI command parser
-│       │   ├── thermal_chamber.py       # Thermal chamber simulator
-│       │   ├── power_supply.py          # Power supply simulator
-│       │   └── multimeter.py            # DMM simulator
-│       │
-│       ├── server/                      # Simulation server
-│       │   ├── __init__.py
-│       │   ├── tcp_server.py            # Async TCP server
-│       │   └── main.py                  # Server entry point
-│       │
-│       ├── transport/                   # Communication layer
-│       │   ├── __init__.py
-│       │   ├── base.py                  # Transport protocol
-│       │   ├── tcp.py                   # TCP/IP implementation
-│       │   └── async_tcp.py             # Async TCP implementation
-│       │
-│       ├── drivers/                     # Instrument SCPI drivers
-│       │   ├── __init__.py
-│       │   ├── base.py                  # Driver base class
-│       │   ├── thermal_chamber.py       # Chamber SCPI driver
-│       │   ├── power_supply.py          # PSU SCPI driver
-│       │   └── multimeter.py            # DMM SCPI driver
-│       │
-│       ├── hal/                         # Hardware Abstraction Layer
-│       │   ├── __init__.py
-│       │   ├── interfaces.py            # Protocol definitions
-│       │   ├── factory.py               # Instrument factory
-│       │   └── impl/                    # HAL implementations
-│       │       ├── __init__.py
-│       │       ├── thermal_chamber.py
-│       │       ├── power_supply.py
-│       │       └── multimeter.py
-│       │
-│       ├── executive/                   # Test execution framework
-│       │   ├── __init__.py
-│       │   ├── sequencer.py             # Test sequencer
-│       │   ├── context.py               # Test context
-│       │   ├── logger.py                # Test logger
-│       │   ├── limits.py                # Limit checker
-│       │   └── models.py                # Domain models
-│       │
-│       ├── tests/                       # DVT test implementations
-│       │   ├── __init__.py
-│       │   ├── base.py                  # Test base class
-│       │   ├── tempco.py                # TempCo characterisation
-│       │   └── load_regulation.py       # Load regulation test
-│       │
-│       ├── data/                        # Data persistence
-│       │   ├── __init__.py
-│       │   ├── repository.py            # Data access layer
-│       │   ├── models.py                # Data models
-│       │   └── migrations/              # Schema migrations
-│       │
-│       ├── reporting/                   # Report generation (Phase 3)
-│       │   ├── __init__.py
-│       │   ├── generator.py             # Report generator
-│       │   ├── pdf.py                   # PDF output
-│       │   ├── html.py                  # HTML output
-│       │   └── templates/               # Report templates
-│       │
-│       ├── api/                         # REST API (Phase 2)
-│       │   ├── __init__.py
-│       │   ├── main.py                  # FastAPI app
-│       │   └── routes/
-│       │       ├── __init__.py
-│       │       ├── instruments.py
-│       │       ├── tests.py
-│       │       └── runs.py
-│       │
-│       ├── dashboard/                   # Streamlit dashboard
-│       │   ├── __init__.py
-│       │   ├── app.py                   # Main Streamlit app
-│       │   ├── pages/                   # Multi-page app
-│       │   │   ├── 01_instruments.py
-│       │   │   ├── 02_run_test.py
-│       │   │   └── 03_results.py
-│       │   └── components/              # Reusable UI components
-│       │       ├── __init__.py
-│       │       └── instrument_panel.py
-│       │
-│       ├── cli/                         # Command-line interface
-│       │   ├── __init__.py
-│       │   └── main.py                  # Typer CLI app
-│       │
-│       └── config/                      # Configuration handling
+│       ├── cli.py                      # Command-line interface
+│       ├── config.py                   # YAML loading
+│       └── dashboard/                  # Streamlit dashboard
 │           ├── __init__.py
-│           ├── models.py                # Pydantic config models
-│           └── loader.py                # Config file loader
+│           └── app.py                  # Main Streamlit app
 │
-├── tests/                               # Test suite
-│   ├── conftest.py                      # pytest fixtures
-│   ├── unit/
-│   │   ├── test_physics_engine.py
-│   │   ├── test_scpi_parser.py
-│   │   ├── test_thermal_model.py
-│   │   └── ...
-│   └── integration/
-│       ├── test_instrument_communication.py
-│       ├── test_tempco_sequence.py
-│       └── ...
+├── tests/                              # pytest test suite
+│   ├── conftest.py                     # pytest fixtures
+│   ├── unit/                           # Unit tests
+│   └── integration/                    # Integration tests
 │
-├── config/                              # Configuration files
-│   ├── default.yaml                     # Default configuration
-│   └── example_pyvisa.yaml              # Example for real hardware
+├── config/                             # Configuration files
+│   └── default.yaml                    # Default configuration
 │
-├── docker/
-│   ├── Dockerfile.server                # Simulation server image
-│   ├── Dockerfile.app                   # Test application image
-│   └── docker-compose.yml               # Full stack orchestration
-│
-└── scripts/
-    ├── demo.py                          # Demo script
-    └── run_tempco.py                    # Example test execution
+└── docker/                             # Docker deployment
+    ├── Dockerfile.server               # Simulation server image
+    ├── Dockerfile.app                  # Test application image
+    └── docker-compose.yml              # Full stack orchestration
 ```
 
 ### 2.2 Package Dependencies
 
 ```
-thermaulate/
-├── cli/           ──────────────────────────────────────────────┐
-├── api/           ──────────────────────────────────────────────┤
-├── dashboard/     ──────────────────────────────────────────────┤
-│                                                                 │
-│   ┌─────────────────────────────────────────────────────────┐  │
-│   │                    PRESENTATION                          │  │
-│   └─────────────────────────────────────────────────────────┘  │
-│                              │                                  │
-│                              ▼                                  │
-├── executive/     ◄───────────────────────────────────────────────┤
-├── tests/         ◄───────────────────────────────────────────────┤
-├── reporting/     ◄───────────────────────────────────────────────┤
-│                                                                 │
-│   ┌─────────────────────────────────────────────────────────┐  │
-│   │                    APPLICATION                           │  │
-│   └─────────────────────────────────────────────────────────┘  │
-│                              │                                  │
-│                              ▼                                  │
-├── hal/interfaces ◄───────────────────────────────────────────────┤
-│                                                                 │
-│   ┌─────────────────────────────────────────────────────────┐  │
-│   │                    DOMAIN (Abstractions)                 │  │
-│   └─────────────────────────────────────────────────────────┘  │
-│                              │                                  │
-│                    implements│                                  │
-│                              ▼                                  │
-├── hal/impl       ◄───────────────────────────────────────────────┤
-├── drivers/       ◄───────────────────────────────────────────────┤
-├── transport/     ◄───────────────────────────────────────────────┤
-├── data/          ◄───────────────────────────────────────────────┤
-│                                                                 │
-│   ┌─────────────────────────────────────────────────────────┐  │
-│   │                    INFRASTRUCTURE                        │  │
-│   └─────────────────────────────────────────────────────────┘  │
-│                                                                 │
-└─────────────────────────────────────────────────────────────────┘
+Dependency Graph:
 
-SIMULATION SERVER (Separate Process):
-├── physics/       ◄─── Pure domain logic, no external dependencies
-├── instruments/   ◄─── Depends on physics
-└── server/        ◄─── Depends on instruments
+app/ ──────────────▶ framework/ ──────────────▶ instruments/
+  │                      │                           │
+  │                      ▼                           │
+  │                   data/ ◀────────────────────────┘
+  │                      ▲
+  ▼                      │
+reporting/ ──────────────┘
+
+simulation/ ─────────────────────────────────▶ instruments/
+
+Key:
+- app/         : CLI, dashboard, config loading (PRESENTATION)
+- framework/   : Test runner, logger, limits (APPLICATION)
+- instruments/ : Interfaces, drivers, transport, SCPI (DOMAIN)
+- data/        : Persistence layer (INFRASTRUCTURE)
+- reporting/   : Report generation (standalone)
+- simulation/  : Physics engine, virtual instruments (DEVELOPMENT)
 ```
 
 ---
 
 ## 3. Module Specifications
 
-### 3.1 Physics Module
+### 3.1 Instruments Package
 
-**Responsibility**: Simulate coupled thermal-electrical behaviour.
+**Responsibility**: Everything about talking to lab instruments.
 
 **Key Components**:
 
 | Component | File | Purpose |
 |-----------|------|---------|
-| PhysicsEngine | `engine.py` | Main simulation loop, state management |
-| ThermalModel | `thermal.py` | Heat transfer calculations |
-| ElectricalModel | `electrical.py` | Current/voltage relationships |
-| DUTBase | `dut/base.py` | Abstract DUT interface |
-| LDOModel | `dut/ldo.py` | LDO voltage regulator implementation |
+| Interfaces | `instruments/interfaces.py` | IThermalChamber, IPowerSupply, IMultimeter protocols |
+| SCPIParser | `instruments/scpi.py` | Parse SCPI command strings |
+| Factory | `instruments/factory.py` | Create instrument sets from config |
+| Transport | `instruments/transport/` | TCP, VISA connection layer |
+| Drivers | `instruments/drivers/` | SCPI command implementations |
+
+**Command Processing Flow**:
+```
+High-level call → Driver → SCPI command → Transport → Instrument
+```
+
+---
+
+### 3.2 Simulation Package
+
+**Responsibility**: Physics simulation for development without real hardware.
+
+**Key Components**:
+
+| Component | File | Purpose |
+|-----------|------|---------|
+| Server | `simulation/server.py` | TCP server hosting virtual instruments |
+| PhysicsEngine | `simulation/physics/engine.py` | Main simulation loop |
+| ThermalModel | `simulation/physics/thermal.py` | Heat transfer calculations |
+| DUTBase | `simulation/physics/models/base.py` | Abstract DUT interface |
+| LDOModel | `simulation/physics/models/ldo.py` | LDO voltage regulator model |
+| VirtualChamber | `simulation/virtual/chamber.py` | Virtual thermal chamber |
+| VirtualPSU | `simulation/virtual/power_supply.py` | Virtual power supply |
+| VirtualDMM | `simulation/virtual/multimeter.py` | Virtual multimeter |
 
 **State Management**:
 - Engine maintains global simulation time
@@ -429,108 +387,68 @@ SIMULATION SERVER (Separate Process):
 
 ---
 
-### 3.2 Instruments Module
+### 3.3 Framework Package
 
-**Responsibility**: SCPI-compliant virtual instrument behaviour.
+**Responsibility**: Test execution infrastructure.
 
 **Key Components**:
 
 | Component | File | Purpose |
 |-----------|------|---------|
-| InstrumentBase | `base.py` | Common instrument functionality |
-| SCPIParser | `scpi_parser.py` | Parse SCPI command strings |
-| ThermalChamberSim | `thermal_chamber.py` | Chamber simulation |
-| PowerSupplySim | `power_supply.py` | PSU simulation |
-| MultimeterSim | `multimeter.py` | DMM simulation |
-
-**Command Processing Flow**:
-```
-SCPI String → Parser → Command Object → Instrument Handler → Response
-```
+| TestRunner | `framework/runner.py` | Sequences test steps |
+| TestContext | `framework/context.py` | Runtime context |
+| TestLogger | `framework/logger.py` | Measurement logging |
+| LimitChecker | `framework/limits.py` | Pass/fail evaluation |
+| Models | `framework/models.py` | TestStatus, TestResult, etc. |
 
 ---
 
-### 3.3 Transport Module
+### 3.4 Data Package
 
-**Responsibility**: Low-level communication.
+**Responsibility**: Data persistence for test results.
 
 **Key Components**:
 
 | Component | File | Purpose |
 |-----------|------|---------|
-| Transport Protocol | `base.py` | Abstract transport interface |
-| TCPTransport | `tcp.py` | Synchronous TCP implementation |
-| AsyncTCPTransport | `async_tcp.py` | Async TCP implementation |
+| Repository | `data/repository.py` | Data access layer |
+| Models | `data/models.py` | TestRun, Measurement dataclasses |
 
 ---
 
-### 3.4 Drivers Module
+### 3.5 Reporting Package
 
-**Responsibility**: Instrument-specific SCPI command sets.
+**Responsibility**: Report generation from stored data.
 
 **Key Components**:
 
 | Component | File | Purpose |
 |-----------|------|---------|
-| DriverBase | `base.py` | Common driver functionality |
-| ThermalChamberDriver | `thermal_chamber.py` | Chamber SCPI commands |
-| PowerSupplyDriver | `power_supply.py` | PSU SCPI commands |
-| MultimeterDriver | `multimeter.py` | DMM SCPI commands |
+| Generator | `reporting/generator.py` | Creates reports from data |
+| Templates | `reporting/templates/` | Report templates |
 
 ---
 
-### 3.5 HAL Module
+### 3.6 App Package
 
-**Responsibility**: Hardware abstraction interfaces.
+**Responsibility**: Application entry points.
 
 **Key Components**:
 
 | Component | File | Purpose |
 |-----------|------|---------|
-| Protocols | `interfaces.py` | Abstract interfaces |
-| InstrumentFactory | `factory.py` | Creates instrument sets from config |
-| HAL Implementations | `impl/*.py` | Concrete HAL classes |
-
----
-
-### 3.6 Executive Module
-
-**Responsibility**: Test execution orchestration.
-
-**Key Components**:
-
-| Component | File | Purpose |
-|-----------|------|---------|
-| TestSequencer | `sequencer.py` | Run test sequences |
-| TestContext | `context.py` | Runtime context |
-| TestLogger | `logger.py` | Measurement logging |
-| LimitChecker | `limits.py` | Pass/fail evaluation |
-| Domain Models | `models.py` | Measurement, Result, etc. |
-
----
-
-### 3.7 Dashboard Module
-
-**Responsibility**: Real-time visualisation via Streamlit.
-
-**Key Components**:
-
-| Component | File | Purpose |
-|-----------|------|---------|
-| Main App | `app.py` | Streamlit application entry point |
-| Instruments Page | `pages/01_instruments.py` | Live instrument status |
-| Run Test Page | `pages/02_run_test.py` | Test execution interface |
-| Results Page | `pages/03_results.py` | Historical results viewer |
-| Instrument Panel | `components/instrument_panel.py` | Reusable instrument display |
+| CLI | `app/cli.py` | Command-line interface (Typer) |
+| Config | `app/config.py` | YAML loading, instance creation |
+| Dashboard | `app/dashboard/app.py` | Streamlit application |
 
 ---
 
 ## 4. Interface Definitions
 
-### 4.1 HAL Interfaces
+### 4.1 Instrument Interfaces
 
 ```python
-# thermaulate/hal/interfaces.py
+# py_dvt_ate/instruments/interfaces.py
 
 from typing import Protocol, runtime_checkable
 
@@ -664,7 +582,7 @@ class ITestLogger(Protocol):
 ### 4.2 Transport Interface
 
 ```python
-# thermaulate/transport/base.py
+# py_dvt_ate/instruments/transport/base.py
 
 from typing import Protocol
 
@@ -701,7 +619,7 @@ class Transport(Protocol):
 ### 4.3 Test Interface
 
 ```python
-# thermaulate/executive/models.py
+# py_dvt_ate/framework/models.py
 
 from dataclasses import dataclass, field
 from datetime import datetime
@@ -778,12 +696,12 @@ class ITest(Protocol):
 ### 4.4 Factory Interface
 
 ```python
-# thermaulate/hal/factory.py
+# py_dvt_ate/instruments/factory.py
 
 from dataclasses import dataclass
 from typing import Literal
 
-from thermaulate.hal.interfaces import IThermalChamber, IPowerSupply, IMultimeter
+from py_dvt_ate.instruments.interfaces import IThermalChamber, IPowerSupply, IMultimeter
 
 
 @dataclass
@@ -827,22 +745,19 @@ class InstrumentFactory:
     @staticmethod
     def _create_simulated(config: InstrumentConfig) -> InstrumentSet:
         """Create simulated instruments."""
-        from thermaulate.transport.tcp import TCPTransport
-        from thermaulate.drivers.thermal_chamber import ThermalChamberDriver
-        from thermaulate.drivers.power_supply import PowerSupplyDriver
-        from thermaulate.drivers.multimeter import MultimeterDriver
-        from thermaulate.hal.impl.thermal_chamber import ThermalChamberHAL
-        from thermaulate.hal.impl.power_supply import PowerSupplyHAL
-        from thermaulate.hal.impl.multimeter import MultimeterHAL
+        from py_dvt_ate.instruments.transport.tcp import TCPTransport
+        from py_dvt_ate.instruments.drivers.chamber import ThermalChamberDriver
+        from py_dvt_ate.instruments.drivers.power_supply import PowerSupplyDriver
+        from py_dvt_ate.instruments.drivers.multimeter import MultimeterDriver
 
         chamber_transport = TCPTransport(config.simulator_host, config.chamber_port)
         psu_transport = TCPTransport(config.simulator_host, config.psu_port)
         dmm_transport = TCPTransport(config.simulator_host, config.dmm_port)
 
         return InstrumentSet(
-            chamber=ThermalChamberHAL(ThermalChamberDriver(chamber_transport)),
-            psu=PowerSupplyHAL(PowerSupplyDriver(psu_transport)),
-            dmm=MultimeterHAL(MultimeterDriver(dmm_transport)),
+            chamber=ThermalChamberDriver(chamber_transport),
+            psu=PowerSupplyDriver(psu_transport),
+            dmm=MultimeterDriver(dmm_transport),
         )
 
     @staticmethod
@@ -954,7 +869,7 @@ All instruments implement these standard commands:
 ### 5.5 SCPI Parser Specification
 
 ```python
-# thermaulate/instruments/scpi_parser.py
+# py_dvt_ate/instruments/scpi.py
 
 from dataclasses import dataclass
 
@@ -1071,7 +986,7 @@ P_diss = (V_in - V_out) × I_load + V_in × I_q
 ### 6.3 Physics Engine Implementation
 
 ```python
-# thermaulate/physics/engine.py
+# py_dvt_ate/simulation/physics/engine.py
 
 from dataclasses import dataclass
 
@@ -1256,7 +1171,7 @@ Schema:
 ### 7.3 Data Repository Interface
 
 ```python
-# thermaulate/data/repository.py
+# py_dvt_ate/data/repository.py (interface)
 
 from typing import Protocol
 from uuid import UUID
@@ -1366,14 +1281,14 @@ dut:
 
 # Data storage paths
 data:
-  database_path: "./data/thermaulate.db"
+  database_path: "./data/py_dvt_ate.db"
   measurements_dir: "./data/measurements"
   reports_dir: "./data/reports"
 
 # Logging configuration
 logging:
   level: INFO
-  file: "./data/logs/thermaulate.log"
+  file: "./data/logs/py_dvt_ate.log"
   format: "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
 
 # Dashboard (Streamlit)
@@ -1391,7 +1306,7 @@ api:
 ### 8.2 Pydantic Configuration Models
 
 ```python
-# thermaulate/config/models.py
+# py_dvt_ate/app/config.py (config models)
 
 from pydantic import BaseModel, Field
 from typing import Literal
@@ -1449,14 +1364,14 @@ class DUTConfig(BaseModel):
 
 
 class DataConfig(BaseModel):
-    database_path: str = "./data/thermaulate.db"
+    database_path: str = "./data/py_dvt_ate.db"
     measurements_dir: str = "./data/measurements"
     reports_dir: str = "./data/reports"
 
 
 class LoggingConfig(BaseModel):
     level: str = "INFO"
-    file: str = "./data/logs/thermaulate.log"
+    file: str = "./data/logs/py_dvt_ate.log"
     format: str = "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
 
 
@@ -1612,7 +1527,7 @@ class AppConfig(BaseModel):
 
 ```toml
 [project]
-name = "thermaulate"
+name = "py_dvt_ate"
 version = "0.1.0"
 description = "Coupled Physics DVT Simulation Platform"
 requires-python = ">=3.11"
@@ -1648,9 +1563,9 @@ dev = [
 ]
 
 [project.scripts]
-thermaulate = "thermaulate.cli.main:app"
-thermaulate-server = "thermaulate.server.main:main"
-thermaulate-dashboard = "thermaulate.dashboard.app:main"
+py_dvt_ate = "py_dvt_ate.cli.main:app"
+py_dvt_ate-server = "py_dvt_ate.server.main:main"
+py_dvt_ate-dashboard = "py_dvt_ate.dashboard.app:main"
 
 [build-system]
 requires = ["hatchling"]
diff --git a/docs/04_development_plan.md b/docs/04_development_plan.md
index 06f80fc..52b0e3a 100644
--- a/docs/04_development_plan.md
+++ b/docs/04_development_plan.md
@@ -38,7 +38,7 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 **Vertical Slice Strategy:**
 - Sprints 1-3: Foundation + Physics Engine (the core simulation)
 - Sprint 4: Dashboard (see the physics working!)
-- Sprints 5-11: Infrastructure/Plumbing (SCPI, TCP, HAL)
+- Sprints 5-11: Infrastructure/Plumbing (SCPI, TCP, Instruments)
 - Sprints 12-17: Test Framework, CLI, Polish
 
 ---
@@ -79,20 +79,18 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 **Goal:** Define physics interfaces and data structures.
 
 ### Task 2.1: Define thermal state dataclasses
-- Create src/py_dvt_ate/physics/__init__.py
-- Create src/py_dvt_ate/physics/models.py
+- Create src/py_dvt_ate/simulation/physics/models.py
 - Define ThermalState (frozen dataclass)
 - Define ElectricalState (frozen dataclass)
 - **Commit:** "Add physics state dataclasses"
 
 ### Task 2.2: Define DUT base protocol
-- Create src/py_dvt_ate/physics/dut/__init__.py
-- Create src/py_dvt_ate/physics/dut/base.py
+- Create src/py_dvt_ate/simulation/physics/models/base.py
 - Define DUTModel Protocol with method signatures
 - **Commit:** "Add DUT model protocol"
 
 ### Task 2.3: Create physics engine stub
-- Create src/py_dvt_ate/physics/engine.py
+- Create src/py_dvt_ate/simulation/physics/engine.py
 - Define PhysicsEngine class with stub methods
 - Methods return placeholder values
 - **Commit:** "Add physics engine stub"
@@ -109,13 +107,13 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 **Goal:** Implement working physics simulation.
 
 ### Task 3.1: Implement thermal calculations
-- Create src/py_dvt_ate/physics/thermal.py
+- Create src/py_dvt_ate/simulation/physics/thermal.py
 - Implement first-order thermal response calculations
 - Pure functions, no state
 - **Commit:** "Implement thermal calculation functions"
 
 ### Task 3.2: Implement LDO DUT model
-- Create src/py_dvt_ate/physics/dut/ldo.py
+- Create src/py_dvt_ate/simulation/physics/models/ldo.py
 - Implement LDOModel class
 - Temperature-dependent Vout, Iq calculations
 - Power dissipation calculation
@@ -140,8 +138,8 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 **Goal:** Visualise physics engine directly - see something working!
 
 ### Task 4.1: Create dashboard app skeleton
-- Create src/py_dvt_ate/dashboard/__init__.py
-- Create src/py_dvt_ate/dashboard/app.py
+- Create src/py_dvt_ate/app/dashboard/__init__.py
+- Create src/py_dvt_ate/app/dashboard/app.py
 - Basic Streamlit page with title
 - **Commit:** "Add Streamlit dashboard skeleton"
 
@@ -173,7 +171,7 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 
 ### Task 5.1: Define SCPI command dataclass
 - Create src/py_dvt_ate/instruments/__init__.py
-- Create src/py_dvt_ate/instruments/scpi_parser.py
+- Create src/py_dvt_ate/instruments/scpi.py
 - Define SCPICommand dataclass
 - **Commit:** "Add SCPI command dataclass"
 
@@ -196,13 +194,13 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 **Goal:** Create first virtual instrument.
 
 ### Task 6.1: Define instrument base class
-- Create src/py_dvt_ate/instruments/base.py
+- Create src/py_dvt_ate/simulation/virtual/base.py
 - Define BaseInstrument with common functionality
 - Command dispatch mechanism
 - **Commit:** "Add base instrument class"
 
 ### Task 6.2: Create thermal chamber simulator stub
-- Create src/py_dvt_ate/instruments/thermal_chamber.py
+- Create src/py_dvt_ate/simulation/virtual/chamber.py
 - Define ThermalChamberSim class
 - Stub SCPI command handlers
 - **Commit:** "Add thermal chamber simulator stub"
@@ -224,7 +222,7 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 **Goal:** Complete instrument simulators.
 
 ### Task 7.1: Create power supply simulator
-- Create src/py_dvt_ate/instruments/power_supply.py
+- Create src/py_dvt_ate/simulation/virtual/power_supply.py
 - Implement PSU SCPI commands
 - VOLT, CURR, OUTP, MEAS commands
 - **Commit:** "Add power supply simulator"
@@ -234,7 +232,7 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 - **Commit:** "Add power supply simulator tests"
 
 ### Task 7.3: Create DMM simulator
-- Create src/py_dvt_ate/instruments/multimeter.py
+- Create src/py_dvt_ate/simulation/virtual/multimeter.py
 - Implement DMM SCPI commands
 - MEAS:VOLT:DC?, CONF commands
 - **Commit:** "Add multimeter simulator"
@@ -250,8 +248,8 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 **Goal:** Expose instruments over network.
 
 ### Task 8.1: Create async TCP server foundation
-- Create src/py_dvt_ate/server/__init__.py
-- Create src/py_dvt_ate/server/tcp_server.py
+- Create src/py_dvt_ate/simulation/__init__.py
+- Create src/py_dvt_ate/simulation/tcp_server.py
 - Define InstrumentServer class with asyncio
 - **Commit:** "Add async TCP server foundation"
 
@@ -261,7 +259,7 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 - **Commit:** "Implement TCP client handling"
 
 ### Task 8.3: Create server main entry point
-- Create src/py_dvt_ate/server/main.py
+- Create src/py_dvt_ate/simulation/server.py
 - Wire up physics engine and instruments
 - Add CLI command to start server
 - **Commit:** "Add simulation server entry point"
@@ -278,13 +276,13 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 **Goal:** Create client-side communication.
 
 ### Task 9.1: Define transport protocol
-- Create src/py_dvt_ate/transport/__init__.py
-- Create src/py_dvt_ate/transport/base.py
+- Create src/py_dvt_ate/instruments/transport/__init__.py
+- Create src/py_dvt_ate/instruments/transport/base.py
 - Define Transport Protocol class
 - **Commit:** "Add transport protocol definition"
 
 ### Task 9.2: Implement TCP transport
-- Create src/py_dvt_ate/transport/tcp.py
+- Create src/py_dvt_ate/instruments/transport/tcp.py
 - Implement TCPTransport class
 - connect(), write(), read(), query() methods
 - **Commit:** "Implement TCP transport"
@@ -301,19 +299,19 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 **Goal:** Create instrument drivers using transport.
 
 ### Task 10.1: Define driver base class
-- Create src/py_dvt_ate/drivers/__init__.py
-- Create src/py_dvt_ate/drivers/base.py
+- Create src/py_dvt_ate/instruments/drivers/__init__.py
+- Create src/py_dvt_ate/instruments/drivers/base.py
 - Define BaseDriver with transport dependency
 - **Commit:** "Add driver base class"
 
 ### Task 10.2: Implement thermal chamber driver
-- Create src/py_dvt_ate/drivers/thermal_chamber.py
+- Create src/py_dvt_ate/instruments/drivers/chamber.py
 - Methods map to SCPI commands
 - **Commit:** "Add thermal chamber driver"
 
 ### Task 10.3: Implement PSU and DMM drivers
-- Create src/py_dvt_ate/drivers/power_supply.py
-- Create src/py_dvt_ate/drivers/multimeter.py
+- Create src/py_dvt_ate/instruments/drivers/power_supply.py
+- Create src/py_dvt_ate/instruments/drivers/multimeter.py
 - **Commit:** "Add PSU and DMM drivers"
 
 ### Task 10.4: Add driver tests
@@ -323,32 +321,30 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 
 ---
 
-## Sprint 11: Hardware Abstraction Layer
+## Sprint 11: Instrument Interfaces
 
-**Goal:** Create HAL interfaces and implementations.
+**Goal:** Create instrument protocol interfaces and factory.
 
-### Task 11.1: Define HAL protocols
-- Create src/py_dvt_ate/hal/__init__.py
-- Create src/py_dvt_ate/hal/interfaces.py
-- Define IThermalChamber, IPowerSupply, IMultimeter
-- **Commit:** "Add HAL protocol definitions"
+### Task 11.1: Define instrument interface protocols
+- Create src/py_dvt_ate/instruments/interfaces.py
+- Define IThermalChamber, IPowerSupply, IMultimeter protocols
+- **Commit:** "Add instrument interface protocols"
 
-### Task 11.2: Implement HAL wrappers
-- Create src/py_dvt_ate/hal/impl/__init__.py
-- Create HAL implementation classes
-- Wrap drivers with HAL interface
-- **Commit:** "Add HAL implementations"
+### Task 11.2: Ensure drivers implement interfaces
+- Update drivers to satisfy Protocol interfaces
+- Add type hints for interface compliance
+- **Commit:** "Implement instrument interfaces in drivers"
 
 ### Task 11.3: Create instrument factory
-- Create src/py_dvt_ate/hal/factory.py
+- Create src/py_dvt_ate/instruments/factory.py
 - InstrumentSet dataclass
 - InstrumentFactory.create() method
 - **Commit:** "Add instrument factory"
 
-### Task 11.4: Add HAL tests
-- Create tests/unit/test_hal.py
+### Task 11.4: Add instrument interface tests
+- Create tests/unit/test_instruments.py
 - Test factory creates correct types
-- **Commit:** "Add HAL unit tests"
+- **Commit:** "Add instrument interface tests"
 
 ---
 
@@ -357,13 +353,12 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 **Goal:** YAML-based configuration.
 
 ### Task 12.1: Define config models
-- Create src/py_dvt_ate/config/__init__.py
-- Create src/py_dvt_ate/config/models.py
-- Pydantic models for all config sections
+- Create src/py_dvt_ate/app/config.py
+- Define Pydantic models for all config sections
 - **Commit:** "Add configuration Pydantic models"
 
 ### Task 12.2: Implement config loader
-- Create src/py_dvt_ate/config/loader.py
+- Add load_config() function to src/py_dvt_ate/app/config.py
 - Load YAML, validate with Pydantic
 - Environment variable overrides
 - **Commit:** "Implement configuration loader"
@@ -410,25 +405,25 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 **Goal:** Test execution orchestration.
 
 ### Task 14.1: Define test interface and models
-- Create src/py_dvt_ate/executive/__init__.py
-- Create src/py_dvt_ate/executive/models.py
+- Create src/py_dvt_ate/framework/__init__.py
+- Create src/py_dvt_ate/framework/context.py
 - TestStatus enum, TestContext, ITest protocol
-- **Commit:** "Add test executive models"
+- **Commit:** "Add test framework models"
 
 ### Task 14.2: Implement test logger
-- Create src/py_dvt_ate/executive/logger.py
+- Create src/py_dvt_ate/framework/logger.py
 - Log measurements and events
 - **Commit:** "Implement test logger"
 
 ### Task 14.3: Implement limit checker
-- Create src/py_dvt_ate/executive/limits.py
+- Create src/py_dvt_ate/framework/limits.py
 - Evaluate pass/fail against limits
 - **Commit:** "Implement limit checker"
 
-### Task 14.4: Implement test sequencer
-- Create src/py_dvt_ate/executive/sequencer.py
+### Task 14.4: Implement test runner
+- Create src/py_dvt_ate/framework/runner.py
 - Run tests, collect results
-- **Commit:** "Implement test sequencer"
+- **Commit:** "Implement test runner"
 
 ---
 
@@ -443,7 +438,7 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 - **Commit:** "Add DVT test base class"
 
 ### Task 15.2: Implement TempCo test
-- Create src/py_dvt_ate/tests/tempco.py
+- Create src/py_dvt_ate/tests/thermal/tempco.py
 - Temperature sweep logic
 - Vout measurement at each temperature
 - TempCo calculation
@@ -517,40 +512,38 @@ Each sprint is ~1-2 days of work, producing demonstrable progress.
 ## File Dependencies Map
 
 ```
-physics/models.py          → (none)
-physics/dut/base.py        → models.py
-physics/dut/ldo.py         → base.py, models.py
-physics/thermal.py         → models.py
-physics/engine.py          → models.py, thermal.py, dut/base.py
+simulation/physics/models.py         → (none)
+simulation/physics/models/base.py    → models.py
+simulation/physics/models/ldo.py     → base.py, models.py
+simulation/physics/thermal.py        → models.py
+simulation/physics/engine.py         → models.py, thermal.py, models/base.py
 
-dashboard/app.py           → physics/engine.py (Sprint 4, direct connection)
+app/dashboard/app.py                 → simulation/physics/engine.py (Sprint 4)
 
-instruments/scpi_parser.py → (none)
-instruments/base.py        → scpi_parser.py
-instruments/*_sim.py       → base.py, physics/engine.py
+instruments/scpi.py                  → (none)
+simulation/virtual/base.py           → instruments/scpi.py
+simulation/virtual/*.py              → base.py, simulation/physics/engine.py
 
-transport/base.py          → (none)
-transport/tcp.py           → base.py
+instruments/transport/base.py        → (none)
+instruments/transport/tcp.py         → base.py
 
-drivers/base.py            → transport/base.py
-drivers/*.py               → base.py
+instruments/drivers/base.py          → instruments/transport/base.py
+instruments/drivers/*.py             → base.py
 
-hal/interfaces.py          → (none)
-hal/impl/*.py              → interfaces.py, drivers/*.py
-hal/factory.py             → interfaces.py, impl/*.py
+instruments/interfaces.py            → (none)
+instruments/factory.py               → interfaces.py, drivers/*.py
 
-config/models.py           → (none)
-config/loader.py           → models.py
+app/config.py                        → (none)
 
-data/models.py             → (none)
-data/repository.py         → models.py
+data/models.py                       → (none)
+data/repository.py                   → models.py
 
-executive/models.py        → hal/interfaces.py
-executive/*.py             → models.py, data/repository.py
+framework/context.py                 → instruments/interfaces.py
+framework/*.py                       → context.py, data/repository.py
 
-tests/*.py                 → executive/models.py, hal/interfaces.py
+tests/*.py                           → framework/context.py, instruments/interfaces.py
 
-dashboard/app.py           → hal/factory.py (Sprint 17, upgraded)
+app/dashboard/app.py                 → instruments/factory.py (Sprint 17, upgraded)
 ```
 
 ---
@@ -578,7 +571,7 @@ MAJOR.MINOR.PATCH[-PRERELEASE]
 | 3 | `v0.1.0-alpha.1` | Physics engine working | Pre-release |
 | 4 | `v0.1.0-alpha.2` | Visual demo (dashboard) | Pre-release |
 | 8 | `v0.1.0-alpha.3` | Network ready (TCP server) | Pre-release |
-| 11 | `v0.1.0-beta.1` | HAL complete | Pre-release |
+| 11 | `v0.1.0-beta.1` | Interfaces complete | Pre-release |
 | 15 | `v0.1.0-beta.2` | First DVT test runs | Pre-release |
 | 17 | `v0.1.0` | **MVP Complete** | Release |
 
@@ -644,7 +637,7 @@ Maintain `CHANGELOG.md` following [Keep a Changelog](https://keepachangelog.com/
 | 4 | `v0.1.0-alpha.2` | **Visual Demo!** | Interactive Streamlit showing physics |
 | 7 | - | Instruments Done | SCPI simulators respond to commands |
 | 8 | `v0.1.0-alpha.3` | Network Ready | TCP server accepts connections |
-| 11 | `v0.1.0-beta.1` | HAL Complete | Abstraction layer swappable |
+| 11 | `v0.1.0-beta.1` | Interfaces Complete | Instrument layer swappable |
 | 15 | `v0.1.0-beta.2` | First Test | TempCo characterisation runs |
 | 17 | `v0.1.0` | **MVP Complete** | Full end-to-end workflow |
 
diff --git a/pyproject.toml b/pyproject.toml
index cb070f4..1df6d2a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -40,9 +40,9 @@ dev = [
 ]
 
 [project.scripts]
-py-dvt-ate = "py_dvt_ate.cli.main:app"
-py-dvt-ate-server = "py_dvt_ate.server.main:main"
-py-dvt-ate-dashboard = "py_dvt_ate.dashboard.app:main"
+py-dvt-ate = "py_dvt_ate.app.cli:app"
+py-dvt-ate-server = "py_dvt_ate.simulation.server:main"
+py-dvt-ate-dashboard = "py_dvt_ate.app.dashboard.app:main"
 
 [build-system]
 requires = ["hatchling"]
diff --git a/src/py_dvt_ate/app/__init__.py b/src/py_dvt_ate/app/__init__.py
new file mode 100644
index 0000000..23cccea
--- /dev/null
+++ b/src/py_dvt_ate/app/__init__.py
@@ -0,0 +1,5 @@
+"""Application entry points.
+
+Contains CLI, dashboard, and configuration loading for the
+py_dvt_ate application.
+"""
diff --git a/src/py_dvt_ate/cli/main.py b/src/py_dvt_ate/app/cli.py
similarity index 100%
rename from src/py_dvt_ate/cli/main.py
rename to src/py_dvt_ate/app/cli.py
diff --git a/src/py_dvt_ate/app/dashboard/__init__.py b/src/py_dvt_ate/app/dashboard/__init__.py
new file mode 100644
index 0000000..30e6600
--- /dev/null
+++ b/src/py_dvt_ate/app/dashboard/__init__.py
@@ -0,0 +1,5 @@
+"""Streamlit dashboard for real-time monitoring.
+
+Provides visualisation of instrument status, test progress,
+and historical results.
+"""
diff --git a/src/py_dvt_ate/cli/__init__.py b/src/py_dvt_ate/cli/__init__.py
deleted file mode 100644
index 429eb26..0000000
--- a/src/py_dvt_ate/cli/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-"""Command-line interface."""
diff --git a/src/py_dvt_ate/config/__init__.py b/src/py_dvt_ate/config/__init__.py
deleted file mode 100644
index da7746f..0000000
--- a/src/py_dvt_ate/config/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-"""Configuration handling."""
diff --git a/src/py_dvt_ate/dashboard/__init__.py b/src/py_dvt_ate/dashboard/__init__.py
deleted file mode 100644
index 92d819f..0000000
--- a/src/py_dvt_ate/dashboard/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-"""Streamlit dashboard."""
diff --git a/src/py_dvt_ate/drivers/__init__.py b/src/py_dvt_ate/drivers/__init__.py
deleted file mode 100644
index c1a69ab..0000000
--- a/src/py_dvt_ate/drivers/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-"""Instrument SCPI drivers."""
diff --git a/src/py_dvt_ate/executive/__init__.py b/src/py_dvt_ate/executive/__init__.py
deleted file mode 100644
index 0b6b2cb..0000000
--- a/src/py_dvt_ate/executive/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-"""Test execution framework."""
diff --git a/src/py_dvt_ate/framework/__init__.py b/src/py_dvt_ate/framework/__init__.py
new file mode 100644
index 0000000..07cf042
--- /dev/null
+++ b/src/py_dvt_ate/framework/__init__.py
@@ -0,0 +1,5 @@
+"""Test execution framework.
+
+Provides test sequencing, measurement logging, limit checking,
+and runtime context management for DVT characterisation tests.
+"""
diff --git a/src/py_dvt_ate/hal/__init__.py b/src/py_dvt_ate/hal/__init__.py
deleted file mode 100644
index c60f8ce..0000000
--- a/src/py_dvt_ate/hal/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-"""Hardware Abstraction Layer."""
diff --git a/src/py_dvt_ate/hal/impl/__init__.py b/src/py_dvt_ate/hal/impl/__init__.py
deleted file mode 100644
index b428c1e..0000000
--- a/src/py_dvt_ate/hal/impl/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-"""HAL implementations."""
diff --git a/src/py_dvt_ate/instruments/__init__.py b/src/py_dvt_ate/instruments/__init__.py
index e769979..fc2da60 100644
--- a/src/py_dvt_ate/instruments/__init__.py
+++ b/src/py_dvt_ate/instruments/__init__.py
@@ -1 +1,9 @@
-"""Virtual instrument implementations."""
+"""Instrument control package.
+
+This package provides everything needed to communicate with lab instruments:
+- Protocol interfaces (IThermalChamber, IPowerSupply, IMultimeter)
+- SCPI command parsing
+- Transport layer (TCP, VISA)
+- Instrument drivers
+- Factory for creating configured instrument sets
+"""
diff --git a/src/py_dvt_ate/instruments/drivers/__init__.py b/src/py_dvt_ate/instruments/drivers/__init__.py
new file mode 100644
index 0000000..444758d
--- /dev/null
+++ b/src/py_dvt_ate/instruments/drivers/__init__.py
@@ -0,0 +1,5 @@
+"""SCPI driver implementations for lab instruments.
+
+Each driver translates high-level operations into SCPI commands
+and handles responses from instruments.
+"""
diff --git a/src/py_dvt_ate/instruments/transport/__init__.py b/src/py_dvt_ate/instruments/transport/__init__.py
new file mode 100644
index 0000000..e682d01
--- /dev/null
+++ b/src/py_dvt_ate/instruments/transport/__init__.py
@@ -0,0 +1,6 @@
+"""Transport layer for instrument communication.
+
+Provides connection abstractions for different backends:
+- TCP sockets (for simulation server)
+- PyVISA (for real instruments)
+"""
diff --git a/src/py_dvt_ate/physics/__init__.py b/src/py_dvt_ate/physics/__init__.py
deleted file mode 100644
index 4c18295..0000000
--- a/src/py_dvt_ate/physics/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-"""Physics simulation engine."""
diff --git a/src/py_dvt_ate/physics/dut/__init__.py b/src/py_dvt_ate/physics/dut/__init__.py
deleted file mode 100644
index d622472..0000000
--- a/src/py_dvt_ate/physics/dut/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-"""Device Under Test models."""
diff --git a/src/py_dvt_ate/reporting/__init__.py b/src/py_dvt_ate/reporting/__init__.py
new file mode 100644
index 0000000..f73b6a2
--- /dev/null
+++ b/src/py_dvt_ate/reporting/__init__.py
@@ -0,0 +1,5 @@
+"""Report generation.
+
+Generates test reports from stored data in various formats
+including PDF and HTML.
+"""
diff --git a/src/py_dvt_ate/server/__init__.py b/src/py_dvt_ate/server/__init__.py
deleted file mode 100644
index 86403c9..0000000
--- a/src/py_dvt_ate/server/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-"""Simulation server."""
diff --git a/src/py_dvt_ate/simulation/__init__.py b/src/py_dvt_ate/simulation/__init__.py
new file mode 100644
index 0000000..1fe6295
--- /dev/null
+++ b/src/py_dvt_ate/simulation/__init__.py
@@ -0,0 +1,5 @@
+"""Physics simulation package.
+
+Provides virtual instruments backed by a coupled thermal-electrical
+physics engine. Used for development and testing without real hardware.
+"""
diff --git a/src/py_dvt_ate/simulation/physics/__init__.py b/src/py_dvt_ate/simulation/physics/__init__.py
new file mode 100644
index 0000000..a87460e
--- /dev/null
+++ b/src/py_dvt_ate/simulation/physics/__init__.py
@@ -0,0 +1,5 @@
+"""Physics engine for thermal-electrical simulation.
+
+Implements coupled thermal and electrical domain models with
+realistic time constants and temperature-dependent behaviour.
+"""
diff --git a/src/py_dvt_ate/simulation/physics/models/__init__.py b/src/py_dvt_ate/simulation/physics/models/__init__.py
new file mode 100644
index 0000000..ca08517
--- /dev/null
+++ b/src/py_dvt_ate/simulation/physics/models/__init__.py
@@ -0,0 +1,5 @@
+"""Device Under Test (DUT) models.
+
+Provides thermal and electrical models for various device types
+including LDO regulators, op-amps, and other components.
+"""
diff --git a/src/py_dvt_ate/simulation/virtual/__init__.py b/src/py_dvt_ate/simulation/virtual/__init__.py
new file mode 100644
index 0000000..a05cda1
--- /dev/null
+++ b/src/py_dvt_ate/simulation/virtual/__init__.py
@@ -0,0 +1,5 @@
+"""Virtual instrument implementations.
+
+SCPI-compliant virtual instruments that respond like real hardware
+but are backed by the physics simulation engine.
+"""
diff --git a/src/py_dvt_ate/tests/__init__.py b/src/py_dvt_ate/tests/__init__.py
index d8b71b2..93e13d7 100644
--- a/src/py_dvt_ate/tests/__init__.py
+++ b/src/py_dvt_ate/tests/__init__.py
@@ -1 +1,6 @@
-"""DVT test implementations."""
+"""DVT test implementations.
+
+Contains characterisation test suites organised by category:
+- thermal/ - Temperature-related tests (TempCo, etc.)
+- electrical/ - Electrical tests (load regulation, etc.)
+"""
diff --git a/src/py_dvt_ate/tests/electrical/__init__.py b/src/py_dvt_ate/tests/electrical/__init__.py
new file mode 100644
index 0000000..7cfae4d
--- /dev/null
+++ b/src/py_dvt_ate/tests/electrical/__init__.py
@@ -0,0 +1,5 @@
+"""Electrical characterisation tests.
+
+Tests for electrical performance including load regulation,
+line regulation, and output accuracy.
+"""
diff --git a/src/py_dvt_ate/tests/thermal/__init__.py b/src/py_dvt_ate/tests/thermal/__init__.py
new file mode 100644
index 0000000..95f8c7f
--- /dev/null
+++ b/src/py_dvt_ate/tests/thermal/__init__.py
@@ -0,0 +1,5 @@
+"""Thermal characterisation tests.
+
+Tests related to temperature behaviour including temperature
+coefficient (TempCo) measurements and thermal stability.
+"""
diff --git a/src/py_dvt_ate/transport/__init__.py b/src/py_dvt_ate/transport/__init__.py
deleted file mode 100644
index c1c5b60..0000000
--- a/src/py_dvt_ate/transport/__init__.py
+++ /dev/null
@@ -1 +0,0 @@
-"""Communication layer."""