Updated 2017-03-09 23:09:41 by gold

## Introduction edit

gold Here is some eTCL starter code for calculating the Optimal Lot Order Size. Most of the testcases involve replicas or models, using assumptions and rules of thumb.

The inventory_cost equals (ordering_cost*units_sold)/order_quantity + (unit_price*units_sold +holding_cost*order_quantity/2. The optimal order_quantity equals sqrt < (2.*ordering_cost*units_sold)/holding_cost>. In the calculator the holding_cost is calculated over a time period, usually 7 days. The holding_cost is dollars per unit per time interval.

### Pseudocode and Equations

```  price? = raw materials + labor  +  profit
price? = raw materials + heat process
price? = raw materials + labor
average price per unit  = revenue  / units sold```

### Testcases Section

In planning any software, it is advisable to gather a number of testcases to check the results of the program. The math for the testcases can be checked by pasting statements in the TCL console. Aside from the TCL calculator display, when one presses the report button on the calculator, one will have console show access to the capacity functions (subroutines).

#### Testcase 1

table 1printed in tcl wiki format
quantity value comment, if any
testcase number:1
10.0 :cost of ordering 1 item in dollars
50.0 :number of sales per time interval
5.0 :holding cost per time interval
7.0 : time interval days usually 7
1.0 :inventory item trial value
100.0 : order value dollars
1.40 :expected interval for empty shelf days
10.0 :discounted inventory total dollars trial item usually 1 d.

#### Testcase 2

table 2printed in tcl wiki format
quantity value comment, if any
testcase number:2
100.0 :cost of ordering 1 item in dollars
1000.0 :number of sales per time interval
10.0 :holding cost per time interval
7.0 : time interval days usually 7
1.0 :inventory item trial value
10000.0 : order value dollars
0.700 :expected interval for empty shelf days
100.0 :discounted inventory total dollars trial item usually 1 d.

#### Testcase 3

table 3printed in tcl wiki format
quantity value comment, if any
testcase number:3
10.0 :cost of ordering 1 item in dollars
100.0 :number of sales per time interval
10.0 :holding cost per time interval
7.0 : time interval days usually 7
1.0 :inventory item trial value
100.0 : order value dollars
0.700 :expected interval for empty shelf days
10.0 :discounted inventory total dollars trial item usually 1 d.

• Stat

## Appendix Code edit

### appendix TCL programs and scripts

```        # pretty print from autoindent and ased editor
# Wilson lot order size sales calculator
# written on Windows XP on eTCL
# working under TCL version 8.5.6 and eTCL 1.0.1
# gold on TCL WIKI, 10oct2014
package require Tk
namespace path {::tcl::mathop ::tcl::mathfunc}
frame .frame -relief flat -bg aquamarine4
pack .frame -side top -fill y -anchor center
set names {{} {cost of ordering 1 item in dollars:} }
lappend names {number of sales per time interval :}
lappend names {holding cost each item per time interval: }
lappend names {optional, time interval days usually 7 :}
lappend names {optional, wholesale item at inventory trial \$1 :}
lappend names {answers: optimum lot size, number of items: }
lappend names {order value dollars: }
lappend names {expected interval until empty shelf days :}
foreach i {1 2 3 4 5 6 7 8} {
label .frame.label\$i -text [lindex \$names \$i] -anchor e
entry .frame.entry\$i -width 35 -textvariable side\$i
set msg "Calculator for lot order size
from TCL WIKI,
written on eTCL "
tk_messageBox -title "About" -message \$msg }
proc calculate {     } {
global side1 side2 side3 side4 side5
global side6 side7 side8
global discounted_inventory
global testcase_number
incr testcase_number
set side1 [* \$side1 1. ]
set side2 [* \$side2 1. ]
set side3 [* \$side3 1. ]
set side4 [* \$side4 1. ]
set side5 [* \$side5 1. ]
set side6 [* \$side6 1. ]
set side7 [* \$side7 1. ]
set side8 [* \$side8 1. ]
set cost_order  \$side1
set number_sales \$side2
set holding_cost \$side3
set quantity  [/ [* \$cost_order \$number_sales ] \$holding_cost]
set  quantity [sqrt \$quantity ]
set side6 \$quantity
set order_cost [* \$quantity \$cost_order ]
set side7 \$order_cost
set interval \$side4
set shelf_life_per_interval [/ \$quantity \$number_sales ]
set shelf_life_days [* \$shelf_life_per_interval \$interval ]
set side8 \$shelf_life_days
set inventory_trial_value \$side5
set discounted_inventory [* \$inventory_trial_value \$quantity      ]                    }
proc fillup {aa bb cc dd ee ff gg hh} {
.frame.entry1 insert 0 "\$aa"
.frame.entry2 insert 0 "\$bb"
.frame.entry3 insert 0 "\$cc"
.frame.entry4 insert 0 "\$dd"
.frame.entry5 insert 0 "\$ee"
.frame.entry6 insert 0 "\$ff"
.frame.entry7 insert 0 "\$gg"
.frame.entry8 insert 0 "\$hh"
}
proc clearx {} {
foreach i {1 2 3 4 5 6 7 8 } {
.frame.entry\$i delete 0 end } }
proc reportx {} {
global side1 side2 side3 side4 side5
global side6 side7 side8
global testcase_number
global discounted_inventory
console show;
puts "%|table \$testcase_number|printed in| tcl wiki format|% "
puts "&| quantity| value| comment, if any|& "
puts "&| testcase number:|\$testcase_number | |&"
puts "&| \$side1 :|cost of ordering 1 item in dollars |   |&"
puts "&| \$side2 :|number of sales per time interval | |& "
puts "&| \$side3 :|holding cost per time interval| |& "
puts "&| \$side4 :| time interval days usually 7 |  |&"
puts "&|\$side5 :|inventory item trial value |  |&"
puts "&| \$side6:|answers: lot size |  |&"
puts "&| \$side7 :| order value dollars|  |&"
puts "&| \$side8  :|expected interval for empty shelf days|  |&"
puts "&| \$discounted_inventory  :|discounted inventory   total dollars |trial item usually  1 d. |&"

}
frame .buttons -bg aquamarine4
::ttk::button .calculator -text "Solve" -command { calculate   }
::ttk::button .test2 -text "Testcase1" -command {clearx;fillup 10.0 50.0 5.0 7.0  1.0 10.0 100. 1.4}
::ttk::button .test3 -text "Testcase2" -command {clearx;fillup 100.0 1000.0 10.0 7.0   1.0  100. 1.E4 0.70 }
::ttk::button .test4 -text "Testcase3" -command {clearx;fillup 10.00 100.0 10.0 7.0   1.0 10.0  100. 0.70 }
::ttk::button .clearallx -text clear -command {clearx }
::ttk::button .cons -text report -command { reportx }
::ttk::button .exit -text exit -command {exit}
pack  .clearallx .cons .about .exit .test4 .test3 .test2   -side bottom -in .buttons
grid .frame .buttons -sticky ns -pady {0 10}
. configure -background aquamarine4 -highlightcolor brown -relief raised -border 30
wm title . "Lot Order Size Calculator "
```

### Pushbutton Operation

For the push buttons, the recommended procedure is push testcase and fill frame, change first three entries etc, push solve, and then push report. Report allows copy and paste from console.

For testcases in a computer session, the eTCL calculator increments a new testcase number internally, eg. TC(1), TC(2) , TC(3) , TC(N). The testcase number is internal to the calculator and will not be printed until the report button is pushed for the current result numbers. The current result numbers will be cleared on the next solve button. The command { calculate; reportx } or { calculate ; reportx; clearx } can be added or changed to report automatically. Another wrinkle would be to print out the current text, delimiters, and numbers in a TCL wiki style table as
```  puts " %| testcase \$testcase_number | value| units |comment |%"
puts " &| volume| \$volume| cubic meters |based on length \$side1 and width \$side2   |&"  ```