Principles of Systems - Section 2.2

xholonWorkbook.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--Xholon Workbook http://www.primordion.com/Xholon/gwt/ MIT License, Copyright (C) Ken Webb, Mon Nov 25 2024 11:21:04 GMT-0500 (Eastern Standard Time)-->
<XholonWorkbook>

<Notes><![CDATA[
Xholon
------
Title: Principles of Systems - Section 2.2
Description: 
Url: http://www.primordion.com/Xholon/gwt/
InternalName: d2c0be6e5ec998149ba8bb288c20a248
Keywords: 

My Notes
--------
25 Nov 2024

In this workbook I implement the system described by Forrester in section 2.2.
My goal is to create the same results that he reports in Table 2.2 and Figure 2.2c .

It works!

### References
() Jay Forrester, Principles of Systems, 1968
    This book was published 7 years after Forrester's book "Industrial Dynamics.
    It focuses on basic principles, and includes a workbook to help students understand the material.

]]></Notes>  

<_-.XholonClass>
  <InventoryControlSystem/>
  
  <InventoryControl/>
  <Inventory/>
  
  <Cloud superClass="Quantity">
    <Supply/> <!-- an infinite supply of the stuff that makes up the inventory -->
  </Cloud>
  
  <PlotValue superClass="Quantity"/>
 
</_-.XholonClass>

<xholonClassDetails>
  <InventoryControl>
    <port name="supply" connector="../Supply"/>
    <port name="inventory" connector="../Inventory/PlotValue"/>
  </InventoryControl>
  
  <Avatar><Color>red</Color></Avatar>
  <PlotValue xhType="XhtypePurePassiveObject"/>
</xholonClassDetails>

<InventoryControlSystem>
  <Supply val="1000000"/>
  <InventoryControl/>
  <Inventory>
    <PlotValue roleName="Inventory balance" val="1000"/>
    <Plot dataPlotterParams="Inventory,Time (weeks),Inventory (units),./statistics/,stats,1,WRITE_AS_DOUBLE"/>
  </Inventory>
</InventoryControlSystem>

<InventoryControlbehavior implName="org.primordion.xholon.base.Behavior_gwtjs"><![CDATA[
  // this works!
  
  // constants
  const AT = 5;    // AT Adjustment time (weeks)
  const DI = 6000; // DI Desired inventory (units)
  const InitInv = 1000; // initial inventory
  
  // functions
  invErrorF = (di, i) => di - i; // Inventory Error function 
  
var me,
  time,        // TIME (weeks)
  changeInInv, // CI Change in inventory (units)
  inventory,   // I Inventory (units)
  invError,    // IE Inventory error (units)
  orderRate,   // OR Order rate (units/week)
  
beh = {
  postConfigure: function() {
    me = this.cnode.parent();
    me.println(me.name());
    me.println(me.supply);
    me.println(me.inventory);
    // set initial/starting values
    time = 0;
    changeInInv = 0;
    inventory = InitInv;
    invError = invErrorF(DI, inventory);
    orderRate = invError / AT;
    me.println("TIME\tCI\tI\tIE\tOR");
  },
  preAct: function() {
    if (time % 2 == 0) {
      me.println(time + "\t" + Math.round(changeInInv) + "\t" + Math.round(inventory) + "\t" + Math.round(invError) + "\t" + Math.round(orderRate));
      changeInInv = 0;
    }
    me.inventory.val(inventory);
  },
  act: function() {
    time++;
    changeInInv += orderRate;
    if (time % 2 == 0) {
      inventory = inventory + changeInInv;
      invError = invErrorF(DI, inventory);
      orderRate = invError / AT;
    }
  }
}
//# sourceURL=InventoryControlbehavior.js
]]></InventoryControlbehavior>

<SvgClient><Attribute_String roleName="svgUri"><![CDATA[data:image/svg+xml,
<svg width="100" height="50" xmlns="http://www.w3.org/2000/svg">
  <g>
    <title>InventoryControl</title>
    <rect id="InventoryControlSystem/InventoryControl" fill="#98FB98" height="50" width="50" x="25" y="0"/>
    <g>
      <title>Inventory</title>
      <rect id="InventoryControlSystem/Inventory" fill="#6AB06A" height="50" width="10" x="80" y="0"/>
    </g>
  </g>
</svg>
]]></Attribute_String><Attribute_String roleName="setup">${MODELNAME_DEFAULT},${SVGURI_DEFAULT}</Attribute_String></SvgClient>

</XholonWorkbook>