Wow! I Didn’t Know I Could Do That with iThink /STELLA!

Wow!I Didn’t Know I Could Do ThatwithiThink/STELLA! Also known as the Ron Popeil (aka Ronco) approach: “But wait, there’s more!!” Chris Soderquist Pontifex Consulting

Wow. I didn’t know I could… • Use an attribute to determine transit time on conveyor • Use a Weibull distribution to determine product life • Run goodness of fit tests so easily • Link models to organizational "scorecards" • Create a multiplayer game • Excel forms • Build student models with built-in reports, and...more! Plus…Q&A. Learn from each other what you can do with the software

Really Geeky stuff • Attribute to determine transit times • Weibull distributions • Linking models to external analyses (goodness of fit tests) • Linking to organizational scorecards

Linking Attributes to Transit Times Perhaps you want to model… • Clinic operations, where different treatment types have different expected transit times or perhaps… • Logistics where different product types have different shipping times

Using an Attribute to Determine Transit TimesOne Approach • Use 2 chains • Track the attributes entering (or average time) • e.g. treatment = physical vs. sick visit; time=30 min vs. 15 min • Track people (actual units) in other chain

Using an Attribute to Determine Transit TimesOne Approach In this example • Numbers enter (e.g. 5-15) Patient Type = INT(RANDOM(5,15)) • If no one In Exam, patient moves right through process to exam (with a DT delay, so you might wish a small DT) • Once someone is In Exam stop the Becoming Next on List conveyor • PULSE from entering exam • Time in exam = entering exam*DT if using time value; • Value for entering exam will determine time in exam can also use a graphical function to relate patient type

Weibull Survival Times Say you want to model how long a product will last in the installed base… • The Weibull distribution works well for product survivability • mean time till failure; k=shape • Tech doc shows the equation for generating Weibull random numbers • Need a stock to hold units before stamping survival times onto it • Small DT is essential to get individual units • PULSE units onto conveyor to stamp

Weibull Survival Times becomes challenging when there is initial stuff in system • Sometimes you may start off a model with stuff already “in process” • Because you need to stamp products to assign Weibull survival times, you can have an initial stock with everything in it and then quickly PULSE everything (1 at a time) onto the conveyor • This “stamps” the survival time onto the unit

Use Excel to calculate Thiel Statistics for Goodness of Fit • Export model output to Excel • Include real world series plus model series • Thiel statistic calculates % of error attributable to • Bias • Unequal variation • Unequal covariation *In isee systems sample model

Generic templates Software features that support building scorecards and strategy maps Modeling features • Converters (to start) • Sector frames • Stock/flow maps • Generic templates keep it operational (see appendix) • Feedback loops improve Interface features • Numeric displays • Warning flashers • Sliders, knobs (other input devices for testing strategies) • Linking to Excel allows access to pie charts and other interesting dashboard output

Linking to Excel (and dashboard tools) can facilitate course corrections * *made in iDashboard which links to Excel files

Fun Experiences • Multiplayer sims • Including Spreadsheet interfaces • Student reports

Multiplayer Simulations • Link up several control panels to one model • Players/Teams can assume different roles in a system • Easily done with iThink/STELLA and Excel in 9.1 Model

Multiplayer SimulationsHow it’s done Pt.1 • Develop the model • Any arrayed variable inputs need to be pulled out (e.g. orders[A,B] becomes orders A and orders B) • Create tables for each role--I usually put them all in 1 pad and create a page for each role • You may need to duplicate variables

Create a Link from the input fields to another sheet. I put them in vertically Create a Save button which will update the iThink model Multiplayer SimulationsHow it’s done Pt.2 Create a Link from the input fields to 3rd sheet which will take date from iThink/STELLA Use a special equation on control panel to report the last value in a row. e.g. Variable for A’s inventory will be in row 2 in iThink table, so following Index equation says 2:2 =INDEX('Table from model'!2:2,MATCH(9.99999999999E+307,'Table from model'!2:2))

Multiplayer SimulationsHow it’s done Pt.3 Import from the Import sheet. Choose dynamic. Export to the XLS sheet set up to take the table. Choose dynamic.

Multiplayer SimulationsHow it’s done Pt.4 • In the input sheets, have the teams make decisions • Then press Submit decisions to save • This updates the iThink model • Run the model for the chosen period (I use a Simulate button to make it easy to see)

Student Reports • Suppose you want students (or even teams of executive education participants) to hand in reports that show how they progressed through a learning lab • You can create interactive student reports that allow you to get data on simulation runs, notes taken, questions answered, and more • You can even set it up so that students cannot get some challenges/questions until they have solved simpler challenges

Set up Select Print Exports in graph so it will be sent to printer Main Menu Experiments Student Notebook Don’t want student to enter Experiment 2 until after they’ve done Experiment 1. Choose password protect in navigation dialog. Switch a variable in the model on when navigating to this experiment to turn on a feedback loop Select Print Exports in text box so it will be sent to printer

Q&A

Contact Info Chris Soderquist Pontifex Consulting 11 Sargent Street Hanover, NH 03755 (603) 653-0228 Chris.soderquist@pontifexconsulting.com

Wow! I Didn’t Know I Could Do That with iThink /STELLA!