diff --git a/src/index.html b/src/index.html
index cd9f312..8def0ba 100644
--- a/src/index.html
+++ b/src/index.html
@@ -21,6 +21,7 @@
   <script src="logic/knowledge.js"></script>
   <script src="logic/time.js"></script>
   <script src="logic/shelf.js"></script>
+  <script src="logic/arrangment.js"></script>
   <script src="logic/evolution.js"></script>
 
   <script src="view/floor.js"></script>
diff --git a/src/logic/arrangment.js b/src/logic/arrangment.js
new file mode 100644
index 0000000..3a91a8d
--- /dev/null
+++ b/src/logic/arrangment.js
@@ -0,0 +1,116 @@
+const ShelfCount = 17 * 6;
+const InRow = 3 * 6;
+
+// index to abstract coordinates
+function i2ac(index) {
+	const y = Math.floor(index / InRow);
+	const x = (index % InRow);
+	if (y === 5 && x >= 6)
+		return [x + 6, y];
+	return [x, y];
+}
+
+function ac2i(x, y) {
+	return y * InRow + x - (y === 5 && x >= 6) * 6;
+}
+
+// index to grid coordinates
+function i2gc(index) {
+	const [x, y] = i2ac(index);
+	return [x + Number(x > 11) + Number(x > 5), y + Math.floor((y + 1) / 2)];
+}
+
+function gc2i(x, y) {
+	x -= Number(x >= 13) + Number(x >= 6);
+	switch (y) {
+		case 0: y = 0; break;
+		case 2: y = 1; break;
+		case 3: y = 2; break;
+		case 5: y = 3; break;
+		case 6: y = 4; break;
+		case 8: y = 5; break;
+	}
+	return ac2i(x, y);
+}
+
+class Arrangement {
+	generateRandom() {
+		this.products = [...Array(ShelfCount).keys()].map(() => Knowledge.semanticNetwork.getRandom().name);
+		this.clear()
+	}
+
+	constructor(products = []) {
+		this.products = products;
+		this.clear()
+	}
+
+	clear() {
+		this.productsAmount = null;
+		this.productsAttributes = null;
+		this.similarities = null;
+		this.cachedValidity = null;
+		this.similarity = null;
+	}
+
+	clone() {
+		return JSON.parse(JSON.stringify(this.products));
+	}
+
+	simulate() {
+		this.similarities ||= [...Array(ShelfCount)].map(() => 0);
+		this.productsAmount ||= [...Array(ShelfCount)].map(() => 50);
+		this.productsAttributes ||= this.products.map(name => Knowledge.productAttributes.getRandomFor(name));
+
+		this.similarity = 0;
+		this.products.forEach((product, i) => {
+			let similarityWithNeighbours = 0;
+			const neighbours = neighboursByIndex(i);
+			for (const neighbour of neighbours) {
+				similarityWithNeighbours += similarity(product, this.products[neighbour]);
+			}
+			similarityWithNeighbours /= neighbours.length;
+			this.similarities[i] = 1 - similarityWithNeighbours;
+			this.similarity += this.similarities[i];
+		});
+
+		this.similarity /= ShelfCount;
+	}
+
+	async validate() {
+		if (this.cachedValidity)
+			return this.cachedValidity;
+
+		const matchingShelfs = this.products.map(async (product, i) => {
+			if (!this.productsAttributes[i])
+				return;
+			
+			let shelfType = await requestJSONCached('/api/decide', { 
+				method: 'POST',
+				headers: { 'Content-Type': 'application/json' },
+				redirect: 'follow',
+				body: JSON.stringify(this.productsAttributes[i])
+			});
+
+			if (!shelfType)
+				return;
+			shelfType = shelfType[0];
+			return Grid.instance.getShelf(...i2gc(i)).type === shelfType;
+		});
+
+		let m = 0;
+		for (const match of matchingShelfs)
+			switch (await match) {
+			case undefined: 
+			case true:
+				m++;
+			}
+
+		return this.cachedValidity = m / this.productsAttributes.length;
+	}
+
+	async fitness() {
+		if (this.similarity === null) this.simulate();
+		if (this.cachedValidity === null) await this.validate();
+		return (this.cachedValidity + this.similarity) / 2;
+	}
+}
diff --git a/src/logic/evolution.js b/src/logic/evolution.js
index 55f8fb3..c850a9d 100644
--- a/src/logic/evolution.js
+++ b/src/logic/evolution.js
@@ -1,75 +1,3 @@
-const ShelfCount = 17 * 6;
-const InRow = 3 * 6;
-
-// index to abstract coordinates
-function i2ac(index) {
-	const y = Math.floor(index / InRow);
-	const x = (index % InRow);
-	if (y === 5 && x >= 6)
-		return [x + 6, y];
-	return [x, y];
-}
-
-function ac2i(x, y) {
-	return y * InRow + x - (y === 5 && x >= 6) * 6;
-}
-
-// index to grid coordinates
-function i2gc(index) {
-	const [x, y] = i2ac(index);
-	return [x + Number(x > 11) + Number(x > 5), y + Math.floor((y + 1) / 2)];
-}
-
-function gc2i(x, y) {
-	x -= Number(x >= 13) + Number(x >= 6);
-	switch (y) {
-		case 0: y = 0; break;
-		case 2: y = 1; break;
-		case 3: y = 2; break;
-		case 5: y = 3; break;
-		case 6: y = 4; break;
-		case 8: y = 5; break;
-	}
-	return ac2i(x, y);
-}
-
-class Arrangement {
-	generateRandom() {
-		this.products = [...Array(ShelfCount).keys()].map(() => Knowledge.semanticNetwork.getRandom().name);
-		this.productsAmount = null;
-		this.similarities = null;
-	}
-
-	constructor(products = []) {
-		this.products = products;
-		this.productsAmount = null;
-		this.similarities = null;
-	}
-
-	clone() {
-		return JSON.parse(JSON.stringify(this.products));
-	}
-
-	simulate() {
-		this.similarities ||= [...Array(ShelfCount)].map(() => 0);
-		this.productsAmount ||= [...Array(ShelfCount)].map(() => 50);
-
-		this.similarity = 0;
-		this.products.forEach((product, i) => {
-			let similarityWithNeighbours = 0;
-			const neighbours = neighboursByIndex(i);
-			for (const neighbour of neighbours) {
-				similarityWithNeighbours += similarity(product, this.products[neighbour]);
-			}
-			similarityWithNeighbours /= neighbours.length;
-			this.similarities[i] = 1 - similarityWithNeighbours;
-			this.similarity += this.similarities[i];
-		});
-
-		this.similarity /= ShelfCount;
-	}
-}
-
 const PopulationSize = 31 * 2;
 const PopulationToKeep = 0.3;
 const MutationRate = 0.2;
@@ -98,14 +26,15 @@ class Evolution extends Arrangement {
 		this.max_similarity = this.population.reduce((p, c) => Math.max(p, c.similarity || 0), 0);
 	}
 
-	next(days) {
+	async next(days) {
 		for (let i = 0; i < Number(days) - 1; ++i) {
-			this.step(false);
+			await this.step(false);
 		}
-		this.step(true);
+		await this.step(true);
 	}
 
-	step(render = true) {
+
+	async step(render = true) {
 		// Complete previous day
 		this.products = this.population[this.populationIndex].products;
     this.simulate();
@@ -124,7 +53,7 @@ class Evolution extends Arrangement {
 			let newPopulation = [];
 			this.population.sort((a, b) => a.similarity - b.similarity);
 
-			let fitness = this.population.map(({ similarity }) => similarity);
+			let fitness = await Promise.all(this.population.map(arr => arr.fitness()));
 			let sum = fitness.reduce((p, c) => p + c, 0);
 			fitness = fitness.map(f => Math.pow(f / sum, 2));
 
diff --git a/src/logic/knowledge.js b/src/logic/knowledge.js
index b53eeae..18b6b91 100644
--- a/src/logic/knowledge.js
+++ b/src/logic/knowledge.js
@@ -52,6 +52,31 @@ class SemanticNetwork {
 	}
 }
 
+class AttributesSemanticNetwork {
+	constructor(data) {
+		this.entries = {}
+		for (const { nazwa, polka, ...attr } of data) {
+			if (!this.entries[nazwa]) {
+				this.entries[nazwa] = Object.entries(attr).reduce((p, [key, value]) => ({ ...p, [key]: new Set([value]) }), {});
+				continue;
+			}
+
+			for (const [key, value] of Object.entries(attr)) {
+				this.entries[nazwa][key].add(value);
+			}
+		}
+	}
+
+	getRandomFor(productName) {
+		const attributes = this.entries[productName];
+		return attributes && Object.entries(attributes)
+			.reduce((p, [key, values]) => {
+				const r = randomFromSet(values); 
+				return r !== 'nie_dotyczy' ? { ...p, [key]: r } : p;
+			}, {});
+	}
+}
+
 function nearbyStorageUnitsCoords(gridX, gridY) {
   function outsideOfStorageCenter(v) {
     const { x, y, w, h } = StorageCenterLocation
@@ -73,6 +98,22 @@ function nearbyStorageUnitsIndexes(gridX, gridY) {
 }
 
 
+async function loadTsvFile(path, nested = []) {
+	const response = await fetch(path);
+	const text = await response.text();
+
+	const [header, ...rows] = text.split('\n')
+		.map(x => x.trim())
+		.filter(x => x)
+		.map(x => x.split('\t')
+			.map(cell => cell.split(',').map(x => x.trim())));
+		
+	return rows.map(row => 
+		row.reduce((p, c, i) => ({ 
+			...p, 
+			[header[i]]: nested.includes(i) ? c : c[0] }), {}));
+}
+
 class Knowledge {
 
 	/**
@@ -80,51 +121,13 @@ class Knowledge {
 	 */
 	static semanticNetwork
 
-	static async loadFromFile(path) {
-		const response = await fetch(path);
-		const text = await response.text();
-		
-		const [header, ...rows] = text.split('\n')
-			.map(x => x.trim())
-			.filter(x => x)
-			.map(x => x.split('\t')
-				.map(cell => cell.split(',').map(x => x.trim())));
+	static async load() {
+		const [ products, attributes ] = await Promise.all([
+			loadTsvFile('/data/products.tsv', [ 2 ]),
+			loadTsvFile('/data/productsTree.tsv')
+		]);
 
-		const data = rows.map(row => 
-			row.reduce((p, c, i) => ({ 
-				...p, 
-				[header[i]]: i == 2 ? c : c[0] }), {}));
-
-		Knowledge.semanticNetwork = new SemanticNetwork(data);
-	}
-
-	constructor() {
-		Knowledge.semanticNetwork = new SemanticNetwork(definition)
-		Knowledge.arrangement = new Arrangement()
+		Knowledge.semanticNetwork = new SemanticNetwork(products);
+		Knowledge.productAttributes = new AttributesSemanticNetwork(attributes);
 	}
 }
-
-
-
-/*
-keywords:
-  p - powiązane pomieszczenia / miejsca
-  c - category
-
-new Knowledge(`
-	Piłka :c sport,rozrywka, piłka nożna
-	Kubek klubowy :c sport,rozrywka,piłka nożna :p kuchnia
-	Waga łazienkowa :c zdrowie,agd,elektronika :p łazienka
-	Czajnik elektryczny :c agd,elektronika,zdrowie :p kuchnia
-	Widelec :c agd,jedzenie,zastawa kuchenna :p kuchnia
-	Łyżka :c agd,jedzenie,zastawa kuchenna :p kuchnia
-	Nóż stołowy :c agd,jedzenie,zastawa kuchenna :p kuchnia
-	Nóż kuchenny :c agd,gotowanie,przyrząd kuchenny :p kuchnia
-	Deska do krojenia :cagd,gotowanie,przyrząd kuchenny :p kuchnia
-	Gąbki kuchenne :c agd,gotowanie,sprzątanie :p kuchnia
-	Worki na śmieci :c agd,gotowanie,sprzątanie :p kuchnia
-	Miska :c agd,jedzenie,gotowanie,zastawa kuchenna :p kuchnia
-	Laptop :c elektronika,gaming :p biuro,szkoła
-	Telefon :c elektronika :p biuro,szkoła
-`)
-*/
\ No newline at end of file
diff --git a/src/logic/time.js b/src/logic/time.js
index 762b696..263baf2 100644
--- a/src/logic/time.js
+++ b/src/logic/time.js
@@ -57,8 +57,8 @@ class Time {
   /**
    * Add days
    */
-  addDays(days) {
-    Products.instance.next(days);
+  async addDays(days) {
+    await Products.instance.next(days);
     Products.instance.update();
     const ul = document.querySelector('ul#history');
     this.setDay(this.day += Number(days));
diff --git a/src/main.js b/src/main.js
index 1326ab4..fa24462 100644
--- a/src/main.js
+++ b/src/main.js
@@ -14,7 +14,7 @@ window.addEventListener('DOMContentLoaded', async () => {
   const grid = new Grid(gridCanvas);
   const agent = new Agent(agentCanvas);
 
-  await Knowledge.loadFromFile('/data/products.tsv')
+  await Knowledge.load()
   const products = new Products(productsCanvas);
 
 	const fpsElement = document.getElementById('fps');
diff --git a/src/utilities.js b/src/utilities.js
index 614b4d2..9aa390e 100644
--- a/src/utilities.js
+++ b/src/utilities.js
@@ -50,4 +50,32 @@ function pick(array) {
 	return index - 1;
 }
 
-function nice(v) { return  `${(v * 100).toFixed(1)}%` }
\ No newline at end of file
+function unreachable() {
+  throw new Error('unreachable');
+}
+
+function randomFromSet(set) {
+	const r = Math.floor(Math.random() * set.size);
+	let i = 0;
+	for (const value of set.values()) {
+		if (i++ === r)
+			return value;
+	}
+	unreachable();
+}
+
+
+function nice(v) { return  `${(v * 100).toFixed(1)}%` }
+
+async function requestJSONCached(url, params = {}) {
+  const key = url + '\n' + (params?.body || '');
+  if (requestJSONCached.cache.has(key))
+    return requestJSONCached.cache.get(key);
+
+  const response = await fetch(url, params);
+  const json = await response.json();
+  requestJSONCached.cache.set(key, json);
+  return json;
+}
+
+requestJSONCached.cache = new Map();
\ No newline at end of file
diff --git a/src/view/grid.js b/src/view/grid.js
index 768fba7..f90b7cd 100644
--- a/src/view/grid.js
+++ b/src/view/grid.js
@@ -5,6 +5,9 @@ const GRID_FIELD_TYPE = Object.freeze({
 });
 
 class Grid {
+  /**
+   * @type{Grid}
+   */
   static instance;
 
   constructor(canvas) {
@@ -31,6 +34,10 @@ class Grid {
     return this.shelves;
   }
 
+  getShelf(x, y) {
+    return this.shelves[x][y];
+  }
+
   setCanvasSize (canvas) {
     canvas.width = 2000;
     canvas.height = 900;
diff --git a/src/view/timeController.js b/src/view/timeController.js
index e9655bb..4c39cfd 100644
--- a/src/view/timeController.js
+++ b/src/view/timeController.js
@@ -13,7 +13,7 @@ class TimeController {
     }
   }
 
-  readFromDayInput() {
-    Time.instance.addDays(document.getElementById('dayInput').value);
+  async readFromDayInput() {
+    await Time.instance.addDays(document.getElementById('dayInput').value);
   }
 }
\ No newline at end of file