operations management module 4 : process analysis s.balachandran 2007 december 2007

Operations ManagementOperations Management

Module 4 : Module 4 : Process AnalysisProcess Analysis

S.BalachandranS.Balachandran

December 2007 2007

December 2007 © S.Balachandran 2 of 23

In this session . . .In this session . . .

• Process TerminologyProcess Terminology

• Process FlowchartingProcess Flowcharting

• Types of ProcessesTypes of Processes

• Process Performance MetricsProcess Performance Metrics


Process TermsProcess Terms

• ProcessProcess: A sequence of operational steps in : A sequence of operational steps in any part of an organization that takes any part of an organization that takes inputsinputs and and transformstransforms them into them into outputsoutputs

• Cycle TimeCycle Time: : AverageAverage time between time between completions of successive steps in a completions of successive steps in a process process

• UtilizationUtilization: Ratio of the time that a : Ratio of the time that a resource resource is actually activatedis actually activated relative to the time that it relative to the time that it is available for useis available for use


Process FlowchartingProcess Flowcharting

Tasks or operations

Decision Points

Storage areas or queues

Flows of materials or customers

Inspection

D Delay / Waiting


Types of ProcessesTypes of Processes

Single-stage Process

Stage 1

Stage 1 Stage 2 Stage 3

Multi-stage Process


Flowchart Example : Car RepairFlowchart Example : Car Repair

Customer drops off

car

Mechanic makes

diagnosis*

Discuss needed

work with customer*

* = Points critical to the success of the service



Repair authorized

Customer drops off

car

Mechanic makes

diagnosis*

Discuss needed

work with customer*

Customer departs with car

Repair not authorized



Customer drops off

car

Mechanic makes

diagnosis*

Discuss needed

work with customer*



Service visible to customerRepair authorized




Customer drops off

car

Mechanic makes

diagnosis*

Discuss needed

work with customer*


Checkparts

availability†

Order parts

Parts available

Parts not available



Perform work†

* = Points critical to the success of the service † = Points at which failure is most often experienced



Customer drops off

car

Mechanic makes

diagnosis*

Discuss needed

work with customer*


Checkparts

availability†

Perform work†

Order parts

Inspect/ test and repair

Perform corrected

work

Corrective work necessary


Parts not available

Parts available


Repair complete




Customer drops off

car

Mechanic makes

diagnosis*

Discuss needed

work with customer*


Checkparts

availability†

Order parts

Service not visible to customer


Parts available


Perform work†


Perform corrected

work


Parts not available

Repair complete





Customer drops off

car

Mechanic makes

diagnosis*

Discuss needed

work with customer*


Collect payment

Notify customer

Checkparts

availability†

Order parts

Repair complete


Parts available


Service not visible to customer

Perform work†


Perform corrected

work


Parts not available



Flowchart Example : HospitalFlowchart Example : Hospital

Process: Emergency room admissionSubject: Ankle injury patientBeginning: Enter emergency roomEnding: Leave hospital

Step no.

Time (min)

Distance (ft)

Summary

Number of stepsActivity

Time (min)

Distance (ft)

Transport Operation

Inspect

StoreDelay

Step description

Insert Step

Append Step

Remove Step



1 Enter emergency room, approach patient window 2 Sit down and fill out patient history3 Nurse escorts patient to ER triage room4 Nurse inspects injury5 Return to waiting room

6 Wait for available bed 7 Go to ER bed8 Wait for doctor9 Doctor inspects injury and questions patient

10 Nurse takes patient to radiology

11 Technician x-rays patient12 Return to bed in ER13 Wait for doctor to return14 Doctor provides diagnosis and advice15 Return to emergency entrance area

16 Check out17 Walk to pharmacy18 Pick up prescription 19 Leave the building

Step no.

Time (min)

Distance (ft)

Summary


Time (min)

Distance (ft)

Transport Operation

Inspect

StoreDelay

Step description

Insert Step

Append Step

Remove Step




Figure 3.8


1 0.50 15 X Enter emergency room, approach patient window 2 10.0 - X Sit down and fill out patient history3 0.75 40 X Nurse escorts patient to ER triage room4 3.00 - X Nurse inspects injury5 0.75 40 X Return to waiting room

6 1.00 - X Wait for available bed 7 1.00 60 X Go to ER bed8 4.00 - X Wait for doctor9 5.00 - X Doctor inspects injury and questions patient

10 2.00 200 X Nurse takes patient to radiology

11 3.00 - X Technician x-rays patient12 2.00 200 X Return to bed in ER13 3.00 - X Wait for doctor to return14 2.00 - X Doctor provides diagnosis and advice15 1.00 60 X Return to emergency entrance area

16 4.00 - X Check out17 2.00 180 X Walk to pharmacy18 4.00 - X Pick up prescription 19 1.00 20 X Leave the building

Step no.

Time (min)

Distance (ft)

Summary


Time (min)

Distance (ft)

Transport Operation

Inspect

StoreDelay

Step description

Insert Step

Append Step

Remove Step









Step no.

Time (min)

Distance (ft)

Summary


Time (min)

Distance (ft)

Transport 9 11 815 Operation 5 23 —

Inspect 2 8 —

Store — — —Delay 3 8 —

Step description

Insert Step

Append Step

Remove Step


Process Flow TermsProcess Flow Terms

• BufferingBuffering− Storage areaStorage area between process stagesbetween process stages where output of a stage is where output of a stage is

placed prior to being used in a downstream stageplaced prior to being used in a downstream stage

• BlockingBlocking– Occurs when the Occurs when the activitiesactivities in a process stage in a process stage must stopmust stop because because

there is there is no place to depositno place to deposit the item just completed the item just completed– If there is no room for an employee to place a unit of work down, If there is no room for an employee to place a unit of work down,

the employee will the employee will hold on to ithold on to it not able to continue working on the not able to continue working on the next unitnext unit

• StarvingStarving– Occurs when the Occurs when the activitiesactivities in a stage in a stage must stopmust stop because because there is there is

no workno work – If an employee is If an employee is waiting waiting at a work station and no work is coming at a work station and no work is coming

to the employee to process, the employee to the employee to process, the employee will remain idlewill remain idle until the until the next unit of work comes next unit of work comes


Process Flow TermsProcess Flow Terms

• BottleneckBottleneck– Occurs when the Occurs when the limited capacitylimited capacity of a process step of a process step

causes causes work to pile upwork to pile up or become or become unevenly distributedunevenly distributed in in the flow of a processthe flow of a process

– If an If an employee or machineemployee or machine works too slow in a works too slow in a multi-multi-stage processstage process, work will begin to , work will begin to pile uppile up in front of that in front of that employee or machine. In this case the employee employee or machine. In this case the employee represents the represents the limited capacitylimited capacity causing the bottleneck. causing the bottleneck.

• PacingPacing– Refers to the Refers to the fixed timingfixed timing of the of the movementmovement of items of items

through the process (e.g., Conveyor Belt in Assembly through the process (e.g., Conveyor Belt in Assembly Line)Line)


Generic Process TypesGeneric Process Types

• Make-to-orderMake-to-order

– Only Only activatedactivated in response to an in response to an actual orderactual order

– InventoryInventory : both work-in-process and finished : both work-in-process and finished

goods kept to a goods kept to a minimumminimum

• Make-to-stockMake-to-stock

– Process Process activatedactivated to meet expected or to meet expected or forecast forecast

demanddemand

– Customer orders are served from Customer orders are served from target stocking target stocking

levellevel


Process Performance MetricsProcess Performance Metrics• Operation time = Setup time + Operation time = Setup time + Run timeRun time

• Throughput time = Average time for a unit toThroughput time = Average time for a unit tomove through the systemmove through the system

• Velocity = Velocity = Throughput timeThroughput time Value-added timeValue-added time

• Cycle time = Average time between completion of unitsCycle time = Average time between completion of units• Throughput rate = Throughput rate = 1 1 ..

Cycle timeCycle time• Efficiency = Efficiency = Actual outputActual output

Standard OutputStandard Output• Productivity = Productivity = OutputOutput

InputInput

• Utilization = Utilization = Time ActivatedTime Activated Time AvailableTime Available


Performance Metrics - LinkagesPerformance Metrics - Linkages


Reducing Throughput TimeReducing Throughput Time

• Eliminate unnecessary activitiesEliminate unnecessary activities

• Perform activities in parallel Perform activities in parallel

• Change the sequence of activitiesChange the sequence of activities

• Reduce interruptions and delaysReduce interruptions and delays

• Reduce duration of bottleneck activitiesReduce duration of bottleneck activities

Use Flowcharts to analyse ProcessUse Flowcharts to analyse Process

operations management module 4 : process analysis s.balachandran 2007 december 2007

Documents

car mechanic

car repaircustomer

needed work

points critical

authorized service visible

service flowchart example

experiencedflowchart

hospitalflowchart example