7 Scheduling_ppt Final

7/26/2019 7 Scheduling_ppt Final

1/31

2007 Pearson Education 2007 Pearson Education

Operations Management

Topic : Scheduling.

Dr.Nitin Kubde.


2/31


How Scheduling

fits the Operations Management

Philosophy

Operations As a CompetitiveWeapon

Operations StrategyProject Management Process Strategy

Process AnalysisProcess Performance and Quality

Constraint ManagementProcess LayoutLean Systems

Supply Chain StrategyLocation

Inventory Managementorecasting

Sales and Operations Planning!esource Planning

Scheduling


3/31


Scheduling

Scheduling: The allocation of resources oer ti!e

to acco!plish specific tas"s.

Demand scheduling: # t$pe of scheduling

%hereb$ custo!ers are assigned to a definite ti!efor order fulfill!ent.

Workforce scheduling: # t$pe of scheduling that

deter!ines %hen e!plo$ees %or".

Operations scheduling: # t$pe of scheduling in%hich &obs are assigned to %or"stations or

e!plo$ees are assigned to &obs for specified ti!e

periods.


4/31


Scheduling

Customer Demand

Three !ethods are co!!onl$ used to schedule

custo!er de!and:

(1) Appointmentsassign specific ti!es for serice

to custo!ers.

(2) Reservationsare used %hen the custo!er

actuall$ occupies or uses facilities associated

%ith the serice.

(3) acklogs!

' The custo!er is gien a due date for thefulfill!ent a product order( or

' #llo% a bac"log to deelop as custo!ers arrie

at the s$ste!. )usto!ers !a$ neer "no%

e*actl$ %hen their orders %ill be fulfilled


5/31


Scheduling Employees

Rotating schedule: # schedule that rotates

e!plo$ees through a series of %or"da$s or hours.

"i#ed schedule: # schedule that calls for each

e!plo$ee to %or" the sa!e da$s and hours each%ee".

$onstraints: The technical constraints i!posed on

the %or"force schedule are the resources proided

b$ the staffing plan and the re+uire!ents placed on

the operating s$ste!.

,ther constraints( including legal and behaioral

considerations( also can be i!posed.


6/31


What is Operations Scheduling


7/31


Objecties of Operations

Scheduling


8/31


Discussion


9/31


Discussion !cont"


10/31


Purpose Of Scheduling

Enables a fir! to allocate production capacit$ to

!eet custo!er re+uire!ents

Scheduling for da$ to da$ actiities

Proides a co!petitie adantage


11/31


Scheduling Methods

"or%ard Scheduling

ack%ard Scheduling

Scheduling methods depends on volume of production

and the nature of operation&


12/31


#orward Scheduling

-hen the actual production actiities

starts

Deter!ines the start and finish ti!es of

the &ob

-P inentor$ leel is high


13/31


$ac%ward Scheduling

Schedules according to the due dates

Deter!ines the latest ti!es.

/asicall$ done in serice organiations.


14/31


SCHED&'()* +C,(-(,(ES

Operations schedulesare short1ter! plansdesigned to i!ple!ent the !aster productionschedule. ,perations scheduling focuses on ho% best to use

e*isting capacit$. ,ften( seeral &obs !ust be processed at one or !ore

%or"stations. T$picall$( a ariet$ of tas"s can beperfor!ed at each %or"station.

'o shop: # fir! that specialies in lo%1 to

!ediu!1olu!e production and utilies &ob or batchprocesses.

"lo% shop: # fir! that specialies in !ediu!1 tohigh1olu!e production and utilies line orcontinuous processes.


15/31


Sh

ippingDepartment

ShippingDepartment

Manufacturing ProcessManufacturing Process

Ra%

)aterials

Ra%

)aterials

*egend!*egend!

atch of partsatch of parts

WorkstationWorkstation


16/31


.ob Shop

Dispatching

Dispatching:# !ethod of generating schedules in &obshops %hereb$ the decision about %hich &ob to process ne*tis !ade using si!ple priorit$ rules %heneer the %or"stationbeco!es aailable for further processing.

+riorit, se-uencing rules: The rules that specif$ the&ob processing se+uence %hen seeral &obs are %aiting in lineat a %or"station.

$ritical ratio ($R):# ratio that is calculated b$ diiding

the ti!e re!aining until a &obs due date b$ the total shop ti!ere!aining for the &ob.CR =(Due date Todays date)/Total shop time remaining(Due date Todays date)/Total shop time remaining

Total Shop Ti!e3 Setup( processing( !oe( and e*pected%aiting ti!es of all re!aining operations( including the operationbeing scheduled.


17/31


.arliest due date (.DD):# priorit$ se+uencingrule that specifies that the &ob %ith the earliest due

date is the ne*t &ob to be processed.

"irst/come0 first/served ("$"S):# priorit$se+uencing rule that specifies that the &ob arriing

at the %or"station first has the highest priorit$.

Shortest processing time (S+):# priorit$se+uencing rule that specifies that the &ob re+uiring

the shortest processing ti!e is the ne*t &ob to be

processed.

.ob Shop Dispatching


18/31


Slack per remaining operations (SRO)!#

priorit$ se+uencing rule that deter!ines

priorit$ b$ diiding the slac" b$ the nu!ber

of operations that re!ain( including the one

being scheduled.

.ob Shop

Dispatching

S45, 3 66Due dateS45, 3 66Due date

Toda$s date8 Total shop ti!e re!aining8Toda$s date8 Total shop ti!e re!aining8

Nu!ber of operations re!aining Nu!ber of operations re!aining


19/31


Performance Measures

'o flo% time: The a!ount of ti!e a &ob spends in theserice or !anufacturing s$ste!. #lso referred to asthroughput timeor time spent in the system, including service.

akespan: The total a!ount of ti!e re+uired to co!plete a

group of &obs. +ast due6Tardiness8: The a!ount of ti!e b$ %hich a &ob

!issed its due date or the percentage of total &obs processedoer so!e period of ti!e that !issed their due dates.

Work/in/process(W+)inentor$: #n$ &ob that is %aiting

in line( !oing fro! one operation to the ne*t( being dela$ed(being processed( or residing in a se!i1finished state.

otal inventor,: The su! of scheduled receipts and on1hand inentories.

4tili5ation: The percentage of %or" ti!e that isproductiel$ spent b$ an e!plo$ee or !achine.


20/31


*antt Charts

6antt chart: are si!ple bar charts that can beused to schedule an$ t$pe of operation

The chart ta"es t%o basic for!s: 698 the &ob or actiit$

progress chart( and 628 the %or"station chart. The 6antt progress chartgraphicall$ displa$s the

current status of each &ob or actiit$ relatie to its

scheduled co!pletion date.

The 6antt %orkstation chartsho%s the load onthe %or"stations and the nonproductie ti!e.


21/31


*antt Progress Chart*antt Progress Chart

+l,mouth

"ord

+ontiac

'o 728 722 723 727 729 72:72171; 71< 71=

$urrent$urrentdatedate

Scheduled actiit$ ti!e

#ctual progress

Start activity

inish activity

!onproductive time

antt Progress )hart for an #uto Parts )o!pan$


22/31


*antt Wor%station Chart*antt Wor%station Chart

antt -or"station )hart for ;ospital ,perating 5oo!s


23/31


.ohnson/s 0ule

'ohnson>s rule: # procedure that !ini!ies !a"espan%hen scheduling a group of &obs on t%o %or"stations.

Step 9.


24/31


Eli!inate >= fro! consideration. The ne*t shortest ti!e

is >2 at -or"station 9( so schedule >2 first.Eli!inate >? fro! consideration. The ne*t shortest ti!e is

>9 at %or"station @9( so schedule >9 ne*t.

Eli!inate >9 and the onl$ &ob re!aining to be

scheduled is >A.

E1ample 2345.ohnson/s 0ule.ohnson/s 0uleat theat the orris achine $o&orris achine $o&

ime (hr)ime (hr)

otorotor Workstation 1Workstation 1 Workstation 2Workstation 2

11 1212 2222

22 77 9933 99 33

77 1919 1:1:

99 1818 ? ne*t to last.


25/31


Workstation

2(7)

1(12)

7(19)

9(18)

3(9)

dle@availalefor further %ork

8 9 18 19 28 29 38Da,

39 78 79 98 99 :8 :9

dle2 2(9)1(22)

7(1:)

9(


26/31


Scheduling $y ,ype Of

Operations

Different for different t$pes of operations

,ypes of Operations

Bob ,peration

5epetitie ,perations

Cabor ntensie ,perations

Serices ,perations

Scheduling .obs for


27/31


Scheduling .obs forMultiple

Wor%stations Priorit$ se+uencing rules can be used to schedule !ore than

one operation. Each operation is treated independentl$.

dentif$ing the best priorit$ rule to use at a particular operation

in a process is a co!ple* proble! because the output fro! one

process beco!es the input for another. )o!puter si!ulation !odelsare effectie tools to deter!ine

%hich priorit$ rules %or" best in a gien situation.

-hen a %or"station beco!es idle( the priorit$ rule is applied to

the &obs %aiting for that operation( and the &ob %ith the highest

priorit$ is selected. -hen that operation is finished( the &ob is !oed to the ne*t

operation in its routing( %here it %aits until it again has the

highest priorit$.


28/31


Single/dimension rules: # set of rules such as


29/31


'abor6limited

Enironments

The li!iting resource thus far has been the nu!ber of

!achines or %or"stations aailable. # !ore t$pical constraint

is the a!ount of labor aailable.

*aor/limited environment: #n eniron!ent in %hich

the resource constraint is the a!ount of labor aailable( notthe nu!ber of !achines or %or"stations.

24 +ssign personnel to the wor%station with the job that has

been in the system longest4

74 +ssign personnel to the wor%station with the most jobs

waiting for processing4

84 +ssign personnel to the wor%station with the largest

standard wor% content4

94 +ssign personnel to the wor%station with the job that has

the earliest due date4


30/31


'in%ing Operations

Scheduling to the Supply Chain

Advanced planning and scheduling (A+S)s,stems!S$ste!s that see" to opti!ie resources acrossthe suppl$ chain and align dail$ operations %ith strategicgoals.


31/31


,han% :ou

Documents

7 Scheduling_ppt Final