Toyota Way Principles

Jugar embodies the Toyota Production System (TPS) principles to ensure quality and reliability.

"The right process will produce the right results." — Toyota Way

Core Principles

Mieruka (Visual Control)

"Make problems visible"

In Jugar:

• Telemetry overlays enabled by default in dev builds
• Visual debugging shows physics bodies, AI paths, collision shapes
• No hidden state - everything is inspectable

#![allow(unused)]
fn main() {
// Enable debug visualization
let config = JugarConfig {
    debug_overlay: true,
    show_physics_bodies: true,
    show_ai_paths: true,
    ..Default::default()
};
}

Poka-Yoke (Error Proofing)

"Mistake-proof the process"

In Jugar:

• Rust's type system prevents null pointers and unhandled errors
• Option<T> and Result<T, E> enforce explicit error handling
• Type-safe entity selectors in Probar

#![allow(unused)]
fn main() {
// Compile-time error prevention
let entity: Entity = world.spawn();  // Cannot be null
let pos: Option<&Position> = world.get_component(entity);

// Must handle the Option
match pos {
    Some(p) => println!("Position: {:?}", p),
    None => println!("Entity has no position"),
}
}

Jidoka (Autonomation)

"Stop and fix problems immediately"

In Jugar:

• Fail-fast on invalid state with console_error_panic_hook
• Never continue with corrupted state
• Tests fail immediately on assertion failure

#![allow(unused)]
fn main() {
// Fail-fast on invalid state
impl World {
    pub fn add_component<T>(&mut self, entity: Entity, component: T) {
        if !self.is_alive(entity) {
            panic!("Cannot add component to dead entity");  // Jidoka
        }
        // ...
    }
}
}

Heijunka (Leveling)

"Level the workload"

In Jugar:

• Fixed timestep logic (fixed_dt) ensures consistent physics
• Works identically on 30fps mobile and 144Hz monitors
• No frame-rate dependent behavior

#![allow(unused)]
fn main() {
const FIXED_DT: f32 = 1.0 / 60.0;  // 60 updates per second

// Physics runs at fixed rate regardless of frame rate
while accumulator >= FIXED_DT {
    physics_update(FIXED_DT);
    accumulator -= FIXED_DT;
}
}

Genchi Genbutsu (Go & See)

"Go to the source to understand"

In Jugar:

• examples/ directory is the source of truth
• Every feature has a working example
• Documentation follows code, not the other way around

# See how physics works
cargo run --example physics_demo

# See how AI works
cargo run --example ai_behavior_tree

# See Probar in action
cargo run --example pong_simulation -p jugar-probar

Just-in-Time (JIT)

"Produce only what is needed, when needed"

In Jugar:

• Assets are streamed on-demand
• Render pipelines are compiled lazily
• Minimal startup time on mobile

#![allow(unused)]
fn main() {
// Lazy asset loading
let texture = assets.load_texture("player.png");  // Deferred
// Texture only loads when first used
}

Kaizen (Continuous Improvement)

"Always be improving"

In Jugar:

• Hot-reloadable assets for rapid iteration
• State serialization for checkpoint/restore
• Makefile kaizen target for improvement analysis

# Run kaizen analysis
make kaizen

# Outputs:
# - Code metrics
# - Coverage analysis
# - Complexity analysis
# - Technical debt grading
# - Improvement recommendations

Quality Metrics

Tiered Workflow

Inspired by Toyota's quality gates:

# Tier 1: ON-SAVE (sub-second)
make tier1  # Type check + fast tests

# Tier 2: ON-COMMIT (1-5 minutes)
make tier2  # Full validation

# Tier 3: ON-MERGE (hours)
make tier3  # Mutation testing + benchmarks