Chapter 2: Supply Chains & Maintenance

Created by Sarah Choi (prompt writer using ChatGPT)

Supply Chains & Maintenance (Spares, Repairs, Consumables)

Props are not isolated objects; they are nodes in a logistics network. When you design with supply chains and maintenance in mind, silhouettes gain purpose, materials carry economic meaning, and factions feel believable under stress. This article gives prop concept artists and production artists a shared framework for encoding spares, repairs, and consumables into design, tying manufacturing realities to faction identity and environment fit.

1) Why logistics should shape form

A prop’s proportions, fasteners, and access panels imply how often it is serviced, by whom, and with what tools. Logistics decisions—local manufacture vs. imported modules, lifetime vs. disposable seals, proprietary vs. standardized connectors—show up as visual language. Design choices that ignore maintenance produce pretty props that collapse under narrative weight. Choices that expose service logic help players read reliability and plan tactics without UI.

2) Maintenance levels and what they mean for silhouette

User level (field). Quick‑release covers, thumb screws, captive fasteners, and color‑blocked consumables. Silhouette shows handles, pull‑tabs, and large negative spaces for glove clearance.

Depot level (workshop). Larger housings unbolt into sub‑assemblies. Orthos include gasketed flanges, alignment dowels, and crane lugs. Silhouette reveals split lines, not hidden.

Factory level (overhaul). Press‑fits, jigs, and specialized fixtures. Exposed datum faces and pallet interfaces. Silhouette may include lift points, QR tags, and transport frames.

Design for the lowest expected maintenance level; upgrade cues upward as needed.

3) Spare philosophies: LRU, SRU, and cannibalization

LRU (Line‑Replaceable Unit). Field swaps of whole modules. Requires keyed connectors, blind‑mate guides, and generous insertion chamfers. The silhouette exposes module seams and latch logic; decals are redundant.

SRU (Shop‑Replaceable Unit). Benchtop disassembly. Requires service screws, torque access, and ESD‑safe surfaces. Silhouette can hide some fasteners but must reveal how a tech would clamp it.

Cannibalization. Factions under scarcity salvage parts. Expect mismatched panel tones, adapter plates, and visible splices. Silhouette becomes patchy; celebrate stitch plates and gussets.

Annotate which philosophy governs each sub‑assembly so modeling and texture choices stay aligned.

4) Consumables: design for flow, not surprise

Consumables (filters, cartridges, belts, seals, abrasive pads, fuel cells) should be visible where change is expected. Size queues (two‑finger vs. whole‑hand), direction arrows, and wear windows turn maintenance into diegetic UI. Place consumables on cool, accessible faces; never in pinch zones. In orthos, call out part numbers and screen‑space minimums so labels remain legible at gameplay distance.

5) Repairability cues you can design into silhouette

  • Fastener dialect. Choose a small family (slot, hex, Torx, rivet) per faction. Repeat pitch and spacing to imply standard kits.
  • Access hierarchy. Outer caps with quarter‑turns; inner covers with machine screws; deep cores with dowels or pins. Express this in step‑downs and gasket lips.
  • Cable management. Service loops, strain reliefs, and keyed plugs placed where hands fit. Don’t hide connectors behind non‑removable parts.
  • Datum logic. Flat pads, corner notches, and locator pins that tell parts how to align. These read as small but decisive silhouette breaks.

6) Manufacturing and supply chain constraints by environment

Desert/dust. Replaceable pre‑filters, purge vents, large clearances, matte finishes. Spare philosophy leans toward LRU with gasket kits.

Arctic/ice. Oversized paddles and seals rated for cold. Avoid tiny fasteners; prefer captive pins. Consumables packaged for glove use.

Jungle/wet. Mold‑resistant elastomers, drain paths, sacrificial coatings. Spare kits include desiccants and anti‑fungals; storage cases have raised feet.

Marine/salt. Duplex stainless, anodized aluminum, isolating washers. Spare kits include anti‑seize and sacrificial anodes; fasteners standardized to resist galling.

Urban/industrial. DIN/ISO standards dominate. Sheet‑metal enclosures with replaceable panels; spare inventories rely on rack units and modular power.

Design these adaptations into ribs, hems, flares, and seal lips—shapes that read even without texture.

7) Faction identity expressed through logistics

  • Frontier Cooperative. Local materials, handcraft repairs, visible patches. Spares are jars of fasteners and gasket rope. Markings are handwritten or stencil.
  • Industrial Syndicate. Heavy sheet‑metal modules, DIN fasteners, interchangeable panels. Spares shipped in crates with pictogram instructions.
  • Clinical Tech Bloc. LRU modules with clean shells, keyed cartridges, and tamper flags. Spares vacuum‑sealed; labels in precise type systems.
  • Lattice Ascendancy. Printed parts re‑grown rather than replaced. Spares are powdered media and feedstock canisters; silhouettes show hopper ports and sinter windows.
  • High Rite Guild. Artisan overhauls on schedule. Spares are ritualized kits; ornament doubles as access code. Screws align to decorative grids.

Keep these dialects consistent across props so players can predict how to service anything from a distance.

8) Packaging, transport, and the wider chain

The supply chain includes how parts move. Cases, pallets, and sling points shape silhouettes when props travel often. Show fork pockets, tie‑down rings, shock mounts, and corner guards. For consumables, design multi‑packs with tear‑away strips and tab geometry that matches the receiving port. Add scannable plates (diegetic QR/UID) on flat faces; reserve enough pixels for in‑engine readability.

9) Inventory philosophy and on‑screen storytelling

High‑inventory worlds show redundant modules clipped to frames and shadow boards with tool silhouettes. Lean worlds display scarcity: empty racks, reworked brackets, multi‑role tools. Put these cues into the prop’s silhouette (extra brackets, empty caddies) rather than relying on environment dressing only.

10) MTBF, wear, and maintenance cycles as form drivers

Mean Time Between Failures (MTBF) shapes the size of vents, the robustness of guards, and the prominence of inspection windows. High‑duty parts earn bigger heat sinks, service clearances, and hinged covers. Low‑duty parts hide deeper. Use rhythm: frequent‑service panels have faster fastener patterns; rare‑service flanges have more bolts with wider spacing.

11) Standards and documentation

Pick a few standards (threads, rail pitches, connector families) and stick to them. Include one‑page “service plates” in concept handoffs: exploded mini‑diagrams with part numbers, torque arrows, seal types, and LRU/SRU labels. These pages become look‑dev guides for decals and normal stamps while keeping the world’s engineering consistent.

12) Texture and material choices that telegraph logistics

Surface finishes should tell repair stories. Brushed planes at service edges, thumb‑polished elastomers on grips, torque‑wrench “witness marks” around bolts, paint ghosts where swapped panels didn’t quite match. For factions with strict QA, show alignment ticks; for salvage cultures, show mismatched hardware and heat‑tint from re‑welds. Keep these reads visible at the first and second read; micro‑grunge alone won’t carry the story.

13) Production survivability: modeling and LOD

Protect silhouette‑critical service features through LOD2: latch hooks, gasket lips, hinge barrels, and pull tabs should remain separate shapes. Bake micro‑fasteners where they are not instructional, but model any fastener that explains disassembly order. Keep minimum edge thickness so tabs survive decimation; specify screen‑space targets for label plates and wear windows.

14) Failure patterns and course corrections

Magic shells. No seams or fasteners; serviceability unclear. Fix: Introduce split lines, datum pads, and access features that align to plausible jigs.

Fastener salad. Too many head types. Fix: Limit to a faction dialect; normalize pitch and spacing.

Hidden consumables. Cartridges buried behind unrelated parts. Fix: Move to exposed faces with keyed geometry and finger clearance.

Texture‑only logistics. Decals pretend to be access panels. Fix: Cut real silhouette steps and gasket lips; let geometry carry the story.

15) Workflow for logistics‑literate design

  1. Define maintenance level and spare philosophy per sub‑assembly.
  2. Choose a fastener and connector dialect; set module pitches.
  3. Place consumables on accessible faces; carve negative space for grips and gloves.
  4. Add service split lines, hinges, and datum pads that read in silhouette.
  5. Embed environment adaptations (seals, drains, anodes) into form.
  6. Create a “service plate” mini‑exploded view with part IDs.
  7. Validate with a blockout and timed “field strip” test in camera.
  8. Lock LOD survival rules for service features and labels.

Supply chains and maintenance are narrative engines. When you design props as participants in repair, replacement, and consumption, every seam and latch becomes a story beat. Build that logic into silhouette and materials, and your factions will feel engineered, your environments will feel lived‑in, and your production team will know exactly how to make it all real in game.