diff --git a/src/app/asset-calculator/asset-calculator.component.html b/src/app/asset-calculator/asset-calculator.component.html
index 60cced5..0187ebc 100644
--- a/src/app/asset-calculator/asset-calculator.component.html
+++ b/src/app/asset-calculator/asset-calculator.component.html
@@ -87,6 +87,9 @@
                 -->
             </div>   
         </form>
+        <input  class="btn btn-secondary col-auto" name="addChangeValue"   
+                [disabled]=assetsDepreciationForm.invalid (click)=addChangeValue()   type="button" value="Dodaj zmianę wartości ">
+                  
 
     </div>
 
diff --git a/src/app/asset-calculator/asset-calculator.component.ts b/src/app/asset-calculator/asset-calculator.component.ts
index 1c9d03c..4a6b23b 100644
--- a/src/app/asset-calculator/asset-calculator.component.ts
+++ b/src/app/asset-calculator/asset-calculator.component.ts
@@ -2,7 +2,7 @@ import {Component,  effect, OnInit, signal } from '@angular/core';
 import {ReactiveFormsModule,  FormGroup, Validators, FormControl} from '@angular/forms';
 import {CurrencyPipe,DecimalPipe,PercentPipe} from '@angular/common';
 import {AssetsModule} from './assets/assets.module'
-import {Asset, Positions, AssetPlanPosition, TypeDepreciation } from './assets/asset';
+import {Asset, Positions, AssetPlanPosition, TypeDepreciation, YearMonth, AssetLifeChange } from './assets/asset';
 import {AssetService} from './assets/service/asset.service'
 
 @Component({
@@ -27,6 +27,11 @@ export class AssetCalculatorComponent implements OnInit{
 
 	// Asset
 
+	addChangeValue() {
+		throw new Error('Method not implemented.');
+	}
+		
+
 
 	positions = new Positions();
 
@@ -40,7 +45,7 @@ export class AssetCalculatorComponent implements OnInit{
 	} );
 
     constructor(private assetService : AssetService ){
-		effect( () => {  this.calculate();});
+		effect( () => {  this.calculate();								});
     }
 
 	ngOnInit(): void{
@@ -48,14 +53,10 @@ export class AssetCalculatorComponent implements OnInit{
 	}
 
 	calculate(){
-		const asset : Asset = {
-			initialValueAsset : this.initialValueAsset(),
-			depreciationRate  : this.depreciationRate(),
-			year  : this.year(),
-			month : this.month(),
-			type  : this.typeDepreciation(),
-			factorValue : this.factorValue() 
-		}
+		const when  = new YearMonth( this.year(), this.month() )
+		const asset = new Asset( this.depreciationRate(),	when, this.typeDepreciation(), this.factorValue() )
+		const creationlifeChange = new AssetLifeChange( when, this.initialValueAsset(), 0, 0 );
+		asset.addChange(creationlifeChange);
 		this.calculateForAsset( asset );
 	}
 
@@ -73,7 +74,7 @@ export class AssetCalculatorComponent implements OnInit{
 
 			sum += position.calculatedDepreciation;
 			position.sum = sum;
-			
+
 			if( 1 == position.when.month ){
 				sumThisYear = position.calculatedDepreciation;
 			}else{
diff --git a/src/app/asset-calculator/assets/asset.ts b/src/app/asset-calculator/assets/asset.ts
index 9e9c758..733fb70 100644
--- a/src/app/asset-calculator/assets/asset.ts
+++ b/src/app/asset-calculator/assets/asset.ts
@@ -3,39 +3,63 @@ export enum TypeDepreciation{
     linear, digressive
 }
 
-export interface Asset {
-    initialValueAsset   : number ;
+export class YearMonth{
+    readonly year  : number ;
+    readonly month : number ;
+    constructor( year: number, month:number ){
+        this.year = year;
+        this.month =month;
+        
+    }
+}
+
+
+export class AssetLifeChange{
+    readonly when           : YearMonth;
+    readonly initial        : number;
+    readonly residual       : number;
+    readonly depreciation   : number;
+    
+    constructor( when        : YearMonth,
+                 initial     : number,
+                 residual    : number,
+                 depreciation: number ){
+        this.when = when;
+        this.initial = initial;
+        this.residual  = residual;
+        this.depreciation  = depreciation;
+    }
+
+}
+
+
+export class Asset {
+    start               : YearMonth ;
     depreciationRate    : number ;
-    type    : TypeDepreciation;
-
-    year                : number;
-    month               : number;
-
+    type                : TypeDepreciation;
     factorValue         : number;
-/*
-    constructor( initialValueAsset : number,
-                 depreciationRate : number,
-                 typeDepreciation    : TypeDepreciation,
-                 year : number,
-                 month: number,
-                 factorValue: number ){
-        this.initialValueAsset = initialValueAsset;
-        this.depreciationRate  = depreciationRate;
-        this.type  = typeDepreciation;
-        this.year  = year;
-        this.month = month;
+    life : AssetLifeChange[]=[];
+
+
+    addChange( change : AssetLifeChange){
+        this.life.push( change );
+    }
+
+    constructor( depreciationRate    : number, 
+                 start : YearMonth,
+                 type  : TypeDepreciation,
+                 factorValue : number ){
+        this.depreciationRate = depreciationRate;
+        this.start = start;
+        this.type  = type;
         this.factorValue = factorValue;
     }
-  */      
+
 }
 
-export class YearMonth{
-    year : number = 0;
-    month :number = 0;
-}
 
 export class AssetPlanPosition{
-    when : YearMonth = new YearMonth();
+    when : YearMonth = new YearMonth(0,0);
     calculatedDepreciation : number = 0;
     sum:number = 0;
     sumThisYear:number = 0;