Mr. D managed service parts inventories for Sundstrand Aviation for over 25 years. He developed and maintained the computer programs used to manage the service parts inventories. When he started at Sundstrand in 1980, inventory planning was done manually using calculators and printouts, but Mr. D wrote the first computerized inventory planning program. Later, he found ways to integrate his planning logic and programs into Sundstrand's new online systems to better manage parts inventories. Now retired, Mr. D offers to share the inventory processes he developed over his career.

1. Who is this Mr. D person?
1
Mr. D managedservice partsinventoriesforSundstrandAviationformore thana quartercentury. This
seriesof papersisabouthowit was done.
My name isMike Dorsey. I’ll call myself Mr.D because writinginthe thirdpersonmakesforeasier
sentence structure andhopefully addedclarity.
I was employedbySundstrand Aviationfrom1977 to 2007. Sundstrandisa manufacturerof aviation
parts and aircraftsystems.
Most of my time at Sundstrand wasspentinservice parts inventoryplanning. I developedand
maintainedthe computerprogramsthatwere usedtomanage the service partsinventories whichwere
soldto the airlinesforrepairof Sundstrandequipment. Intime,the responsibilityforthe repairservices
inventories alsocame undermyspanof control.
From the inventory planningperspective, the mostsalientissueaboutSundstrand’sbusiness isthat
theirproductshave a verylonglife span,are repairable, andare notsubjectto anymarketingpressures
such as advertisingordiscountingprograms.
I feel fortunate tohave hadthe opportunitytoworkat SundstrandwhenIdid. It was the dawnof the
use of computers atSundstrand. My universitytrainingincluded computerprogrammingaswell as
statistics.Because of these skills Iwasable tobuildaninventory planningsystemfromgroundup.
In 1980, whenI firstcame to inventoryplanning there werenocomputerprogramsusedtomanage
sparesinventory. The planningwasdone by three plannersusingprogrammable calculators,andtwo
large stacks of old style IBMgreenstripe fanfoldprintouts.One stackwasthe usage (demand) history.
The secondstack was the currentinventorypositionof on-handstockandopenpurchase orders. To do
the planningthe plannerswould re-typethe datafromthe two reportsintothe calculator,and,the
calculatorwouldtell themif theyneededto ordermore parts. Mostly,theydidn’t. Not an efficient
process! The practical upshot of thiswas that inventory wasincreasingandservice levels were low.
I usedmyprogrammingskillstowrite the firstinventory planningprogram. Thatprogram mergedthe
data fromthe two“printouts”,applied astatistical analysis, andlistedwhatpartsthe planners needed
to order.The program also gave a recommended orderquantity.
One yearintomy planningtenure anew businessmanagementsystemwasimplemented.Itwas called
COOP,whichstandsforCustomerOn-lineOrder Processing. COOPwas a state of the art real time
systemrunon an IBM 360 platform. COOPwas a product of McDonald DouglasAutomation,a
subsidiaryof McDonaldDouglasAviation.
Coop wasa huge leapforwardforthe CustomerService organization. Thisnew on-linesystem
managedcustomerordersfromreceipt,toshipment,toinvoice,tocashcollection. Italsohad inventory
planningcapabilities.However, Ithoughtthe planninglogicusedby COOP wassub-par. Therefore,I
useda feature of the COOP systemthatallowed me todetermine the inventoryplanningparameters
outside of the COOP processes andthen insertthose parametersintothe COOPsystem. The COOP
systemwould thenmanage inventory tomyspecificationsinareal time mode.

2. Who is this Mr. D person?
2
The resultswere greatfortworeasons;First, I usedsimple forecastingand inventory management
techniques. Second, since Ididmyownprogramming, we were fastandflexible.ThismeantIwasable
to accommodate the rapidlychangingbusiness,andwasable toextendthe reachof the system to
additional sectorsof the business –our ownrepairshopsand a program calledOnSite Supportat
several airlinelocations.
In 1999, Sundstrandwassoldto UnitedTechnologiesCorporation.We were mergedwith UTC’s
Hamilton-Standarddivision.In2000, Sundstrand’sbusinesswas converted off of the COOP systemand
put ontothe Hamilton-StandardERPsystem(JDE). However,my “Sundstrand”programs were once
againusedto insertthe inventoryplanning parametersintothe JDEsystem. JDE wouldthenmanage
sparesinventory tomyspecifications.
In 2006 Hamilton-Sundstrandimplementedanoff the shelf solutionforservice partsplanning,andthe
programs I spent25 yearsdevelopingwere thrownonthe scrapheap. I became a dinosaurof sorts.But
unlike the dinosaurs Isawthe meteorcoming. Ipartedwayswith Sundstrand in2007.
In 2008 I workedsix months forCaterpillarLogistics. The CATservice partsbusinesswasmuchlike
Sundstrand’s –repairable productswithalongservice life. Mostly, Iwrote programs that were usedto
reporton inventory performance. Due tothe economiccrashin 2008/2009 I was laidoff fromCAT. I
guessI’mretirednow.
In thisseriesof papers Iwill share withyou some of the processes Ideveloped inthatquartercenturyof
planning. Iwill offeryouasmorgasbordof ideas.Take whatyou like andleave the rest.
I ask that if you use anyof my ideasthat yougive me creditfor my inventions. Justsay“I got this
processfromMr. D”.
January 2016
Contact Mr. D at MisterD@windstream.net withquestions.