The river represents items flowing through your value stream. Fast, clear water means work is moving efficiently. Slow, dark, wide pools mean work is stuck waiting.

Each glowing dot is a unit of work. Watch them speed through stations and pile up in wait zones. The Demand slider controls how many items enter the system — crank it up to see bottlenecks choke.

Taller, wider buildings mean longer processing time. A small hut is a 5-minute step. A large factory is hours of active work.

This is the key insight. The distance between stations shows how long work sits idle. A vast stagnant lake between two buildings means days of waiting — the biggest source of waste in most value streams.

Buildings show cycle time only. Wait time appears as stagnant pools between buildings. This is the classic VSM view — it makes waste viscerally obvious by showing idle time as physical distance.

Buildings absorb wait time — each building shows total time at that station. A dashed red line inside each building marks where processing ends and waiting begins. Use this when each department owns their total lead time.

Each step has a %C&A — the probability that work leaving it is correct. A red bar at the top of a building shows the failure rate. Failed items turn red and flow backward to a specified earlier step (default: the start). Rolled %C&A in the stats panel is the product of all individual %C&A values — the chance a unit makes it through the entire stream without rework.

When a station's WIP exceeds 10, dark ravens gather around the building — one for each unit of excess WIP. They perch on rooftops and circle nearby. When WIP drops, they fly away offscreen. Ravens are a warning: too much work-in-progress means congestion, context switching, and longer lead times.

At 1x speed, a full day takes 24 real hours — you'll only see the day/night cycle at higher speeds (at 1,000x, a day passes in ~86 seconds). Windows glow at night. A wolf howls from the hills. The cycle is cosmetic — it gives the world life.

Parallax background layers add depth. Trees fill the gaps between stations. The environment responds to daylight.

Scroll or Drag to pan  ·  Ctrl+Scroll to zoom  ·  Click the minimap to jump

Speed controls how fast time passes. Demand controls how many items enter the system.

Speed	1 Day	90-Day VSM
1x (real time)	24 hours	90 days
1,000x (default)	86 sec	2.2 hours
10,000x	8.6 sec	13 min
100,000x (max)	0.9 sec	78 sec

See cycle time, wait time, batch size, and tools for each step. Red wait bars highlight the worst offenders.

Your value stream has real costs. The goal is profitability.

Revenue: Each completed item earns $1 per game-minute permanently. More completions = higher revenue rate.

Costs:
• Startup: $500 per station (one-time). More steps = higher startup investment.
• Operating: $0.10/sec per station. The cost of keeping the lights on.
• WIP Carrying: $0.05/sec per item in the system. Inventory is expensive — every item sitting in a queue burns cash.
• Handoff: $0.50 each time a particle enters a station. More stations = more handoffs = more cost.
• Rework: $2.00 each time a particle fails quality. Poor %C&A is financially painful.

Profit = Revenue − All Costs. A lean value stream (low WIP, few steps, high %C&A) reaches profitability fast. A bloated one may run at a loss for months.

R&D Bank: 10% of net profit flows into an R&D fund, represented by a coin fountain near the Product. This is your innovation budget — you can only invest when you're making money.

Relative sizes buildings and gaps for visual clarity, with proportional but compressed scaling. True Time maps pixel width to real time — a 10-day wait is genuinely 10x wider than a 1-day wait. Buildings that would be too small to see get a minimum width with a "not to scale" sign. Switch with the lock icon in the toolbar (switching resets the simulation).

In a traditional VSM diagram, "3-day wait" is just a number in a box. Here, it's a vast dark pool you have to scroll through while watching your work items sit motionless. The medium is the message.

The stats panel (bottom-right) shows your P&L: revenue from completed items vs. operating costs, WIP carrying costs, handoff costs, and rework costs. PCE (Process Cycle Efficiency) shows what fraction of lead time is actual processing. Rolled %C&A shows the probability a work item makes it through without rework. Most real value streams have PCE under 5% — meaning 95% of lead time is pure waste. The economics make this waste visible: every minute of wait time costs you money.