MRP Design Matrix

Design-driven manufacturing for Odoo 18 with lot-level parameters.

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The Problem

Manufacturing companies working on make-to-order basis face a fundamental limitation in Odoo: the standard system manages products as categories, but cannot describe the specific physical item that needs to be produced right now, for this particular customer, with these exact parameters.

The result: engineering departments maintain thousands of product variants (one per parameter combination), or rely on paper-based specifications outside the system. In both cases, planning, traceability, and costing are incomplete.

The Solution

MRP Design Matrix introduces a new conceptual layer: the production lot carries the design specification of the item. The BoM is parametric -- materials and quantities are computed automatically from the lot's parameters. A rule system (matrix) governs the transformation.

Key Concepts

Concept	Description
Lot = Design carrier	stock.lot with Properties describes the specific production run. Variant = category. Lot = physical realization.
BoM = Planning view	Contains all possible materials, including O-variants (conditional items with coeff=0.0).
MO = Execution view	Only active materials appear. O-variants are activated by the matrix (coeff > 0.0).
Design Matrix (T0-T3)	Four rule tables transform design parameters into concrete materials and operations.
Properties, not custom fields	All design parameters live in Odoo Properties. Definitions are data, not code.

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Target Industries

Industry	Key Challenge	Example
Garbage bags	Resin consumption depends on geometry	Width x length x thickness x density
Corrugated boxes	Board grade, liner combo, trim optimization	Multi-layer grammage calculation
Roller shutters	Motor selected by door weight, not user choice	motor_class = f(area x slat_weight)
Security doors	RC class forces minimums on all components	sheet_thickness = max(user, RC_min)
Interior doors	Double-leaf has different geometry	effective_area = w x h x 2

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Module Stack

                                    ┌──────────────────────────────────┐
                                    │   mrp_design_matrix_bags         │
                                    │   mrp_design_matrix_corrugated   │
                                    │   mrp_design_matrix_roller_door  │  Industry
                                    │   mrp_design_matrix_security_door│  Submodules
                                    │   mrp_design_matrix_interior_door│
                                    └──────────────┬───────────────────┘
                                                   │ depends
                                    ┌──────────────▼───────────────────┐
                                    │      mrp_design_matrix           │  Core Engine
                                    │  (models, views, GoRules, UI)    │
                                    └──────────────┬───────────────────┘
                                                   │ depends
                          ┌────────────────────────┼────────────────────────┐
                          │                        │                        │
           ┌──────────────▼──────┐  ┌──────────────▼──────┐  ┌──────────────▼────────────┐
           │ mrp_bom_formula_    │  │ stock_move_forced_  │  │ stock_move_forced_        │
           │ lot_dimension       │  │ lot_multi           │  │ lot_multi_dim             │
           │ (bridge ~50 lines)  │  │ (PR candidate OCA)  │  │ (width/height/thickness)  │
           └──────────────┬──────┘  └─────────────────────┘  └───────────────────────────┘
                          │ depends
           ┌──────────────▼──────────────────┐
           │ mrp_bom_line_formula_template   │  own formula engine (this repo)
           └─────────────────────────────────┘

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Design Matrix -- The Four Tables

T0 -- Constraints

Executes before anything else. Blocks invalid designs or warns about risky ones.

Type	Effect	Example
ERROR	UserError, stops MO creation	Perforation + insulation (roller)
WARNING	message_post, continues	Width > 4000mm + manual drive (roller)

T1 -- Geometry + Forced Values

Computes intermediate variables and enriches the context for T2/T3.

Effect Type	Description	Example
context_modify	Computes new value	effective_length = height x 2 + 50
context_force	Overrides user input with minimum	sheet_thickness = max(user, RC_min)
context_derive	Computes from physics	motor_class = f(area x slat_weight)

T2 -- Materials

Three output types (non-exclusive):

Type	Mechanism	Use Case
O-variant activation	{"bom_line_coeff_key": "ink-O", "coefficient": 1.15}	Activate/deactivate BoM line
Direct ref	{"product_ref": "module.product_xmlid", ...}	Fixed materials without variants
PTAV resolution	{"product_tmpl_ref": "...", "param_attribute_map": {...}}	Design param -> attribute -> variant

T3 -- Operations

Conditionally adds workorders to the MO.

{"workcenter_ref": "module.wc_assembly", "duration_formula": "width * 0.5", "sequence": 10}

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Design Parameters -- Odoo Properties

All industry-specific parameters live in fields.Properties, following the pattern from product_electrical_properties. Only width, height, and thickness remain as real fields.

Definition (XML)

<records>
    <properties code="bags" name="Bags - Standard">
        <items name="bag_type">
            <item name="type">selection</item>
            <item name="selection">[["sleeve","Sleeve"],["sheet","Sheet"]]</item>
            <item name="default">sleeve</item>
        </items>
        <items name="has_tie">
            <item name="type">boolean</item>
            <item name="default">false</item>
        </items>
    </properties>
</records>

Reading (Python)

design_context = {
    "width": lot.width, "height": lot.height, "thickness": lot.thickness,
    "qty": production.product_qty,
    **{k: v for k, v in (lot.design_params or {}).items()},
}
# -> {"width": 600, "bag_type": "sleeve", "has_tie": True, ...}

---

PTAV Resolution

Design parameters map to product attributes, enabling automatic variant selection:

design_params.color = "FF0000"
    | param_attribute_map: {"color": "module.attr_color"}
    v
attribute: Color / value: "FF0000"
    | _get_variant_for_combination(ptav)
    v
product.product: Ink + Color/FF0000

Values in design_params must match product.attribute.value.name exactly.

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Semi-Finished Products -- Recursive Chain

Each semi-finished product gets its own lot with parameters extracted from the parent lot:

End product lot_1: {bag_type, has_tie, width, color, thickness}
    MO Level 1
        |
        +-- Film (semi-finished)
        |       lot_2: {bag_type, width, color, thickness}
        |       <- extracted via param_extraction_map
        |       MO Level 2
        |            |
        |            +-- Resin  mto_stop=True -> PO
        |
        +-- Tie  mto_stop=True -> PO or stock
                lot_3: {tie_length: height + 50}
                <- transformation via safe_eval

mto_stop	Behavior
False	Creates new MO + child lot, recursion continues
True	Searches stock for matching lot -> if none -> PO with parameters

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Matrix Templates -- Workflow

1. Select design_param_definition_id on BoM  ->  lot shows correct Properties
2. Select matrix_template_id  ->  press [Load from Template]
3. Edit the 4 JSON tables with ace_editor    ->  changes are per-BoM
4. Template is NEVER edited directly

Templates are shipped by industry submodules. The customer copies and customizes.

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Data Models

mrp.design.param.definition

Field	Type	Description
code	Char	Unique code: 'bags', 'roller_door'
name	Char	Human-readable name
industry	Char	Grouping/filtering
parent_id	Many2one -> self	Inheritance
design_params_definition	PropertiesDefinition	Parameter schema

mrp.matrix.template

Field	Type	Description
name	Char	Template name
industry	Char	For filtering
constraint_table	Json	T0 rules (GoRules format)
geometry_table	Json	T1 rules
material_table	Json	T2 rules
operation_table	Json	T3 rules

mrp.bom (extended)

Field	Type	Description
design_param_definition_id	Many2one	Parameter set for this BoM
matrix_template_id	Many2one	Template reference (read-only)
constraint_table	Json	T0 -- editable copy
geometry_table	Json	T1 -- editable copy
material_table	Json	T2 -- editable copy
operation_table	Json	T3 -- editable copy

mrp.bom.line (extended)

Field	Type	Description
matrix_coeff_rule	Char	Reference to T2 row for coefficient
coeff_default	Float	0.0 = O-variant, 1.0 = real
product_tmpl_id	Many2one	For PTAV resolution
param_attribute_map	Json	{design_key: attr_external_id}
param_extraction_map	Json	{child_key: source_or_formula}
child_definition_id	Many2one	Child lot parameter set
mto_stop	Boolean	Stops MTO chain at this level

stock.lot (extended)

Field	Type	Description
width / height / thickness	Float	Real fields (from _dim module)
design_param_definition_id	Many2one	Parameter set
design_params	Properties	All industry parameters

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Repository Structure

mrp_design_matrix/
    models/
        mrp_design_param_definition.py
        mrp_matrix_template.py
        mrp_bom.py
        mrp_bom_line.py
        mrp_production.py
        stock_lot.py
    views/
        mrp_bom_views.xml
        mrp_matrix_template_views.xml
        mrp_design_param_definition_views.xml
    data/
        base_param_definitions.xml

mrp_design_matrix_{industry}/
    data/
        design_param_definitions.xml
        install_design_params.xml
        matrix_templates/*.json
    demo/
        demo_bom_{industry}.xml

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Technical Requirements

• Odoo: 18.0 (Community and Enterprise)
• License: AGPL-3
• Dependencies: OCA/Odoo CE modules only
• Rule engine: zen-engine (Rust + Python bindings, <1ms latency, embeddable)
• Pre-commit: ruff, black, OCA checks
• Tests: Required for every module

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Project Plan

Phase	Duration	Key Result
Phase 0 -- Foundation	2 weeks	forced_lot PRs in OCA
Phase 1 -- Bridge	1 week	Formula module sees Properties
Phase 2 -- Core models	2 weeks	All models + UI
Phase 3 -- Core logic	2 weeks	Full MO algorithm end-to-end
Phase 4 -- Industry submodules	3 weeks	5 industry packages
Phase 5 -- OCA submission	1 week	PR submitted

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Risks

Risk	Probability	Mitigation
OCA review requires significant changes	Medium	Early precheck with OCA maintainer
GoRules doesn't cover all T0 cases	Low	cDMN as fallback for constraints
PTAV matching requires exact name match	High	Validation on design_params save
Industry templates are incomplete	Medium	Demo data + documentation for extension

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Credits

Author: Rosen Vladimirov <[email protected]> | Terraros Commerce Ltd.

Inspired by: product_electrical_properties (Properties pattern)

License

This project is dual-licensed: AGPL-3.0 by default, or a commercial license — see LICENSE-COMMERCIAL.md and DUAL_LICENSING.md (contact: [email protected]).