Shell Dep Standards

Shell Design and Engineering Practices (DEPs) serve as the internal "technical law" for Shell projects and operations. They provide standardized requirements and recommendations for the design, construction, and operation of assets to ensure safety, reliability, and cost-efficiency. 🛠️ Core Purpose and Scope

DEPs are a comprehensive repository of engineering wisdom gathered from decades of global operations.

Safety First: Establishes minimum requirements to prevent accidents and protect the environment.

Technical Uniformity: Ensures consistency across different global business units. shell dep standards

Efficiency: Reduces rework and provides a clear framework for contractors and vendors.

Project Lifecycle: Covers everything from initial process engineering to decommissioning. 📚 Key Categories and Structure

The DEPs are categorized by engineering disciplines, often following a specific numbering system (e.g., 31.xx.xx.xx for Mechanical). Shell Design and Engineering Practices (DEPs) serve as

Shell DEP and MESC Standards Overview | PDF | Valve - Scribd

Here’s a feature specification related to Shell Dependency Standards — designed to improve consistency, portability, and maintainability of shell scripts across environments.

1. Specify the Shell Explicitly

Use #!/bin/bash (not /bin/sh) if you need Bash features (arrays, [[ ]], etc.).
For maximum portability, stick to POSIX sh.

4. User Stories

| ID | As a… | I want to… | So that… | |----|-------|-------------|-----------| | US1 | Developer | Declare required shell version in a standard way | My script fails early with a clear error if run in incompatible shell | | US2 | DevOps Engineer | Automatically validate dependencies before script execution | I avoid cryptic runtime errors in CI/CD pipelines | | US3 | System Admin | See optional vs required dependencies at the top of the script | I know what I can safely skip installing | | US4 | Security Reviewer | Scan dependency blocks for unexpected external commands | I reduce supply chain and command-injection risks | Use #

Dependency lifecycle

Add: update deps.txt and include rationale.
Update: change version+checksum, run tests, note changelog.
Remove: remove from deps.txt and cleanup usage + tests.

Step 6: Prepare for Technical Query (TQ) & Deviation Request (DR)

If you cannot meet a DEP clause (e.g., due to material availability or existing design), you must file a DR. Shell’s process demands:

A clear description of the non-compliance.
Risk assessment (HazOp or FMEA style).
Proposed mitigation.
Sign-off from a Shell discipline authority (no local agent can waive major DEPs).

7. Implementation Phases

| Phase | Deliverable | |-------|--------------| | 1 | Specification + parser library in POSIX shell | | 2 | Pre-commit hook to check dependency blocks | | 3 | CI action (GitHub/GitLab) to auto-validate | | 4 | VSCode / IntelliJ plugin with syntax highlighting for dep blocks | | 5 | Community registry of common dependency profiles |