How do I install the Planning skill?

Run npx skillmds@latest add ashfordeou/planning in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Planning safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Planning?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Planning free to use?

Yes. Installing skills from SkillMD is free. This skill is licensed under Apache-2.

Who published Planning?

ashfordeOU (@ashfordeou) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Planning by ashfordeou — Agent Skill

Name: Planning
Author: ashfordeOU

Planning

Use when planning DO-178C software certification for airborne systems or equipment: determine the software level or DAL (A-E) from failure-condition severity, draft the PSAC (Plan for Software Aspects of Certification), and scope planning-phase artifacts such as the PSAC, SDP, SVP, SCM, and SQA plans. Covers ARP4754A FDAL/IDAL allocation and ARP4761A severity-to-DAL propagation, including coverage-depth implications per level: A requires MC/DC, B requires decision coverage, C requires statement coverage, D and E require none. Trigger: DO-178C planning, PSAC, software level determination, DAL assignment, development assurance, certification planning, ARP4754A, ARP4761A, airborne software certification.

ashfordeOU 0897a9c 3 files · 8.0 KB Updated Sep 17, 2026

File contents

DO-178C Planning (avionics/do178c/planning)

Use when the task is DO-178C planning-phase work: drafting a PSAC, determining the software level (DAL) for a function or item, or scoping planning-phase artifacts (PSAC, SDP, SVP, SCM, SQA plans).

Domain quick reference

Software levels (DO-178C): A = Catastrophic, B = Hazardous, C = Major, D = Minor, E = No safety effect.
ARP4754A splits development assurance: FDAL (function) vs IDAL (item); an item's IDAL is the highest FDAL among the functions it implements.
ARP4761A propagates failure-condition severity to DAL.
Coverage depth scales with DAL: A = 100% MC/DC, B = 100% decision, C = 100% statement, D/E = none required.
Accepted means of compliance: AC 20-115D (software), AC 20-174 (ARP4754A).

Workflow

Confirm certification basis and applicable standards.
Determine failure-condition severity per ARP4761A (FHA/PSSA inputs).
Allocate DAL / FDAL / IDAL per ARP4754A + ARP4761A.
Map DAL to DO-178C software level and objectives tables.
Draft PSAC and planning-phase artifacts.

Pitfalls

DAL from severity alone without FDAL/IDAL split.
Coverage depth mismatched to level (A requires MC/DC, not statement).
Traceability gaps (no derived requirements).

Behavior contract (gate 3)

This skill ships its own contract test, like every skill in the library: scripts/test_do178c_levels.py against scripts/do178c_levels.py (stdlib unittest, offline). Run: python3 skills/avionics/do178c/planning/scripts/test_do178c_levels.py

Compliance

Standards referenced, not reproduced: DO-178C / ARP4754A / ARP4761A text is proprietary (RTCA/SAE); summary-only per standards-map.yaml and brief 06.
compliance: STANDARDS-REF, gated: false.

---name: planningdescription: Use when planning DO-178C software certification for airborne systems or equipment: determine the software level or DAL (A-E) from failure-condition severity, draft the PSAC (Plan for Software Aspects of Certification), and scope planning-phase artifacts such as the PSAC, SDP, SVP, SCM, and SQA plans. Covers ARP4754A FDAL/IDAL allocation and ARP4761A severity-to-DAL propagation, including coverage-depth implications per level: A requires MC/DC, B requires decision coverage, C requires statement coverage, D and E require none. Trigger: DO-178C planning, PSAC, software level determination, DAL assignment, development assurance, certification planning, ARP4754A, ARP4761A, airborne software certification.license: Apache-2.0---# DO-178C Planning (avionics/do178c/planning)Use when the task is DO-178C planning-phase work: drafting a PSAC,determining the software level (DAL) for a function or item, or scopingplanning-phase artifacts (PSAC, SDP, SVP, SCM, SQA plans).## Domain quick reference- Software levels (DO-178C): A = Catastrophic, B = Hazardous, C = Major, D = Minor, E = No safety effect.- ARP4754A splits development assurance: FDAL (function) vs IDAL (item); an item's IDAL is the highest FDAL among the functions it implements.- ARP4761A propagates failure-condition severity to DAL.- Coverage depth scales with DAL: A = 100% MC/DC, B = 100% decision, C = 100% statement, D/E = none required.- Accepted means of compliance: AC 20-115D (software), AC 20-174 (ARP4754A).## Workflow1. Confirm certification basis and applicable standards.2. Determine failure-condition severity per ARP4761A (FHA/PSSA inputs).3. Allocate DAL / FDAL / IDAL per ARP4754A + ARP4761A.4. Map DAL to DO-178C software level and objectives tables.5. Draft PSAC and planning-phase artifacts.## Pitfalls- DAL from severity alone without FDAL/IDAL split.- Coverage depth mismatched to level (A requires MC/DC, not statement).- Traceability gaps (no derived requirements).## Behavior contract (gate 3)This skill ships its own contract test, like every skill in the library:scripts/test_do178c_levels.py against scripts/do178c_levels.py (stdlibunittest, offline). Run: python3skills/avionics/do178c/planning/scripts/test_do178c_levels.py## Compliance- Standards referenced, not reproduced: DO-178C / ARP4754A / ARP4761A text is proprietary (RTCA/SAE); summary-only per standards-map.yaml and brief 06.- compliance: STANDARDS-REF, gated: false.

Frequently asked questions