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Lecture Notes #8
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Materials Handlin Data
Materials handling is a means by which total manufacturing costs are reduced through more efcient
Materials handling and storage accounts or 25% o all employees
55% o actory space
8% o production time
$amage to "5% o the products handled
 
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Materials Handlin De!niti"ns
!& Materials handling is the art and science o mo'ing( storing( protecting( and controlling material
 
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#nit L"ad
* central component o any materials handling system is the de+nition o a unit load
* unit load is the single item pic,ed up and mo'ed between two locations * unit load may contain many items
- Not necessarily identical
 
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#nit L"ad $%"nt&'
/0ample 1 heet metal stamping $eli'ery and storage o raw material
- 3nit load 4 * coil o steel
lan,ing operation - 3nit load 4 6allet o blan,s& 7ne coil generates multiple
unit loads o blan,s
tamping operation - 3nit load 4 * rac, o stamped parts& 7ne pallet o blan,s
generates multiple unit loads o rac,s
*ssembly operation - 3nit load 4 7ne 'ehicle body& 7ne rac, o parts is mo'ed
on multiple 'ehicle bodies
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#nit L"ad $%"nt&'
7ten a unit load is a batch o items rom a production process Large unit loads
- Less mo'ement - Larger e)uipment needed or the mo'e - May need larger aisles - Larger oor load capacity
maller unit loads - 7pposite o abo'e
9hat would you e0pect or a :;< system= 9hat perormance system parameter >rom a
)ueuing model perspecti'e? does batching a.ect=
 
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hould you always ha'e the smallest unit loads possible=
/0ample @or a or,lit truc,( empty tra'el unctions in the same
manner as setup times or e)uipment -  <oo much empty tra'el may mean lac, o or,lit capacity
to accommodate mo'e re)uirements
 
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#nit L"ad $%"nt&'
 <he design o a unit load also a.ects and is a.ected by  <he materials handling methodsAe)uipment
- e&g&( human materials handlers  weight and siBe limits  <he storage methods 1 the a'ailability and alternati'es or containers and pallets - e&g&( unit loads in sturdy containers may permit stac,ing
 <he transormation to di.erent unit loads throughout the production process - e&g&( how can pallets >one type o unit load? be loaded
onto trailers >another type o unit load?
 
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Ret(rna)le C"ntainers
Deturnable containers with good stacking and nesting eatures are preerred
/0amples 6lastic totes
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Ret(rna)le C"ntainers * E+a,-le $%"nt&'
tac,able plastic containers that can be nested when empty >pp& !E"!E! <ompin,s et al&? ;nside dimensions >L 0 9 0 H?F !8G 0 !!G 0 !!G
7utside dimensionsF 2G 0 !2G 0 !2G
 <wo empty containers nested  !G high
 <railer dimensions used or container transport - 2G 0 !2G 0 !2G
!& Container space utiliBation torage space in the containerApace re)uired to store
the container
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Ret(rna)le C"ntainers * E+a,-le $%"nt&'
2&Container nesting ratio Container heightA*dditional height when a nested container is
added
& <railer space utiliBation  <otal storage space or the ma0 number o containers in a
trailerA<railer 'olume - 2GA2G 4 !2 containers stored lengthwise
- !2GA!2G 4 ! containers stored widthwise
- !2GA!2G 4 ! containers stored 'ertically
- Ma0 o !2 containers per trailer
 
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& <railer space utiliBation
& <railer return ratio Ma0 number o empty containers in a trailerAMa0 number
o ull containers in a trailer
 
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Materials Handlin S.ste, Desin
*pply the engineering design process !&  $e+ne the system( scope( and obIecti'es
2&  $e'elop the system re)uirements
&  Jenerate alternati'es
&  /'aluate alternati'es
K&  ;mplement
$e'eloping alternati'e materials handling systems by way o procedures and algorithms is much more difcult than or layout  <his is due to the almost in+nite possibilities o items to
 
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Materials Handlin S.ste, Desin $%"nt&'
*s a guide( a set o material handling principles ha'e been de'eloped to help guide and e'aluate designs 6rinciple 1 !& undamental truth( law( etc& upon which others are
based( 2& * rule o conduct(
ee MH 6rinciples presentation
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ome approaches or starting a design !& enchmar,ing and case studies
/0amine other good systems imilar application >e&g&( airports( distribution center(?
imilar technology >e&g&( *Js( power and ree con'eyors?
2& ;dentiy the intent o di.erent types o materials handling e)uipment and match it to speci+c needs Con'eyors
Material mo'ed re)uently between speci+c points
@i0ed path mo'ement
 
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ome approaches or starting a design >cont&?
2& ;dentiy the intent o di.erent types o materials handling e)uipment and match it to speci+c needs >cont&?
;ndustrial 'ehicles ;ntermittent mo'ement andAor mo'ement o'er long distances
Many pic,"upAdrop"o. locations
ariable path mo'ement
HoistsACranes Mo'ement o'er short distances
;ntermittent mo'ement
 
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Materials Handlin S.ste, Desin $%"nt&'
ome approaches or starting a design & torage and retrie'al 3nit load storage systems Larger loads Many design decisions
- torage con+guration - Lane depth - tac, height - *ccess
 
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ome approaches or starting a design & torage and retrie'al
mall load storage systems Jenerally under 5 lbs& per storage location  <ypes
- 7perator to stoc, >e&g&( library shel'ing?
- toc, to operator >e&g&( carousel?  <here are many di.erent types o small load storage systems
- hel'ing
- Cabinets
- Carousels
- *AD
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Materials Handlin S.ste, Desin $%"nt&'
ome approaches or starting a design 5& 3se o automatic identi+cation >*uto ;$?
 <rac,ing material mo'ement and storage is an integral part o MH
 
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Materials Handlin S.ste, Desin $%"nt&'
;t is impossible to re'iew each materials handling and storage option
9e will re'iew selected methodsAcalculations or speci+c aspects o materials handling and storage e&g&( returnable container analysis
 
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Desources or practitioners MH;* 1 Materials Handling ;nstitute o *merica
- httpFAAwww&mhia&orgA Materials handling classics Case studies
C;CMH/ 1 College ;ndustry Council on Materials Handling /ducation - httpFAAwww&mhia&orgAetA/<MH;C;CMH/Home&cm Materials handling ta0onomy
Materials Handling ;nstitute - httpFAAwww&mhia&orgAetAetmhihome&cm oo,s( seminars targeted toward practicing engineers
 <he Material Handling /ducation @oundation( ;nc  - httpFAAwww&mhia&orgAetA/<MH/@Home&cm cholarships
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6ages !E"22
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E+a,-le "/ Desin De%isi"ns $%"nt&'
Carton siBe to use at the pac,aging station( and carton material
6allet siBe( material( and 2"way or "way 6alletiBer Ma0 load height( automatic( manual
Lit truc,s  <ype( capacity( or, height( power source
torage 6allet rac,s( storage depth( access to loads
 <railers $imensions
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$ecisions will a.ect re)uirements or pace
6allets
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/0amples @or,lits
6allet truc,s
@rom"to data
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!& <he system layout
& <rip e0changes bAw wor, centers per unit time
& <he 'ehicle dispatching strategy
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Cal%(latin t0e N(,)er "/ Ind(strial 1e0i%les Re2(ired $%"nt&'
ehicle dispatching problem How load pic, up and deli'ery orders are assigned to
'ehicles or satisaction
$etermines /mpty 'ehicle runs during time t >e&g&( a shit?
 
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Cal%(latin t0e N(,)er "/ Ind(strial 1e0i%les Re2(ired $%"nt&'
 
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Cal%(latin t0e N(,)er "/ Ind(strial 1e0i%les Re2(ired $%"nt&'
*'erage distance a 'ehicle can tra'el in a +0ed time period *ssume dri'ers are always a'ailable
 Average travel speed of a vehicle including
unplanned downtime (distance/time)
 Average time to refuel/recharge
 
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InClass E+er%ise
$e'elop a ormula to calculate the average  distance tra'eled by a single 'ehicle o'er time T Average travel speed of a vehicle including
unplanned downtime (distance/time)
 Average time to refuel/recharge
 
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1 1
Travel distance
m m
ij ij
i j
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  <otal <ra'el $istance 4 E(!55
9hat is one critical re)uirement that is missing here=
 
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6rior calculations only considered loaded 'ehicle tra'el  <his implicitly assumes that a load is immediately
pic,ed"up ater a load drop"o. at the same location
 
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Esti,atin E,-t. 1e0i%le Tra4el
 <hree methods will be presented or estimating empty 'ehicle tra'el  <he method used depends on the siBe and nature o
the operation - Large operation
e more precise since rough estimates may result in a large number o added 'ehicles
 
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Esti,atin E,-t. 1e0i%le Tra4el $%"nt&'
!& *ssume all 'ehicles return to a central dispatching point ater drop"o. o a ull load
; this is the case( then use the actual dispatch location
 
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Need distance data rom the dispatch point to each department
 pointdispatchthetoideptfromDistance idept point todispatchthefromDistance
)departmenttot(departmendataDistance )departmenttot(departmendatato-From
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/stimate total 'ehicle >loaded and empty? tra'el re)uirements
 
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 A B C D E
 A  ""
B ""
C ""
D ""
E ""
 A  ""
B ""
C ""
D ""
E ""
• Total vehicle travel
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Esti,atin E,-t. 1e0i%le Tra4el $%"nt&'
2& *ssume empty 'ehicle tra'el e)uals ull 'ehicle tra'el @or small systems this may be ade)uate
/asy to calculate
& /stimate empty 'ehicle tra'el as a unction o pic,"up and drop"o. acti'ity rom department i
to department j >/gbelu !E8?
 
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*ll deli'eries into dept& i  empty 'ehicles will be a'ailable
    
   
 
   
   
     
   
 
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= =
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∑∑
∑∑
= =
= =
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the matri$ b" the sum of all the from-to data
ki
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E+a,-le $%"nt&'
 
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Esti,atin E,-t. 1e0i%le Tra4el  $%"nt&'
;ntuition  <he elements o the g ij matri0 will always e)ual ∑∑f ij 1 the
sum o all elements in the rom"to chart
-  <he number o empty 'ehicle trips 4 the number o ull 'ehicle trips
;n this method( empty 'ehicle trips rom department i to j  are weighted by the number o trips into department  j and out o department i
- /mpty 'ehicle trips are more li,ely to originate rom departments recei'ing many loads( and more li,ely to terminate at departments sending out many loads&
 
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InClass E+er%ise
 
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Cal%(latin t0e N(,)er "/ Ind(strial 1e0i%les Re2(ired $%"nt&'
∑∑ = =
+=
= =