5 developing a project plan-ii

Developing a Project PlanDeveloping a Project Plan

Planning ProjectsPlanning Projects•• Developing tasksDeveloping tasks

–– Develop the overall scopeDevelop the overall scope–– Work Breakdown schedulesWork Breakdown schedules–– TasksTasks

Scheduling ProjectsScheduling Projects

•• Tasks:Tasks:–– Develop/revise detailed guides for each resource Develop/revise detailed guides for each resource

indicating quantity, quality, and timingindicating quantity, quality, and timing•• Means of Task Accomplishment:Means of Task Accomplishment:

–– Milestone charts for departments, subcontractors, Milestone charts for departments, subcontractors, and suppliers; cash flow schedule; CPM/PERT: and suppliers; cash flow schedule; CPM/PERT: beginbegin--activity and completeactivity and complete--activity dates, and activity dates, and updated activity slackupdated activity slack

•• Timing of Tasks:Timing of Tasks:–– Slightly before project is begun and continued Slightly before project is begun and continued

throughout projectthroughout project

Controlling ProjectsControlling Projects•• Tasks:Tasks:

–– Sense noncompliance of resources with schedules, Sense noncompliance of resources with schedules, standards, and budgets; take corrective actions, shift standards, and budgets; take corrective actions, shift resources, develop alternativesresources, develop alternatives

•• Means of Task Accomplishment:Means of Task Accomplishment:–– Department budget reports, activity cost reports, Department budget reports, activity cost reports,

quality compliance reports, time performance reportsquality compliance reports, time performance reports

•• Timing of Tasks:Timing of Tasks:–– During projectDuring project

SMART CriteriaSMART Criteria

•• Milestones should be:Milestones should be:

–– SSpecificpecific

–– MMeasurableeasurable

–– AAssignablessignable

–– RRealisticealistic

–– TTimeime--framedframed

Project Time Management ProcessesProject Time Management ProcessesProject time management involves the processes required to Project time management involves the processes required to ensure timely completion of a project. Processes include:ensure timely completion of a project. Processes include:–– Activity definitionActivity definition: involves developing a more detailed WBS and : involves developing a more detailed WBS and

supporting explanations to understand all the work to be done sosupporting explanations to understand all the work to be done so you can you can develop realistic duration estimatesdevelop realistic duration estimates

–– Activity duration estimatingActivity duration estimating: : Duration includes the actual amount of Duration includes the actual amount of time worked on an activity plus elapsed timetime worked on an activity plus elapsed time

–– Activity sequencing: Activity sequencing: Involves reviewing activities and determining Involves reviewing activities and determining dependencies so as to use critical path analysisdependencies so as to use critical path analysis

–– Schedule development: Schedule development: creates a realistic project schedule to provide creates a realistic project schedule to provide a basis for monitoring project progress for the time dimension oa basis for monitoring project progress for the time dimension of the project. f the project. Important tools and techniques include Gantt charts, PERT analysImportant tools and techniques include Gantt charts, PERT analysis, critical is, critical path analysis, and critical chain schedulingpath analysis, and critical chain scheduling

–– Schedule controlSchedule control

•• Gantt/bar chartGantt/bar chart

•• Project networkProject network

Visual Tools for Project ManagementVisual Tools for Project Management

Gantt ChartsGantt Charts

•• Gantt charts provide a standard format for displaying project Gantt charts provide a standard format for displaying project schedule information by listing project activities and their schedule information by listing project activities and their corresponding start and finish dates in a calendar formatcorresponding start and finish dates in a calendar format

•• Symbols include:Symbols include:–– A black diamond: A black diamond: milestones or significant events on a milestones or significant events on a

project with zero durationproject with zero duration–– Thick black bars: Thick black bars: summary taskssummary tasks–– Lighter horizontal barsLighter horizontal bars: tasks: tasks–– Arrows: Arrows: dependencies between tasksdependencies between tasks

9

Gantt Chart for Software Launch ProjectGantt Chart for Software Launch Project

10

Sample Tracking Gantt ChartSample Tracking Gantt ChartAs the project progresses, the status of activities is plotted oAs the project progresses, the status of activities is plotted on the chart, n the chart, compared to the plan, and, if necessary, corrective action is tacompared to the plan, and, if necessary, corrective action is takenken

Scheduling and Control ChartsScheduling and Control Charts

•• Horizontal Bar Charts/Gantt Chart (continued)Horizontal Bar Charts/Gantt Chart (continued)–– AdvantagesAdvantages

•• Easy to understandEasy to understand•• Easy to modify and updateEasy to modify and update•• Low costLow cost

–– DisadvantagesDisadvantages•• Cumbersome for large projectCumbersome for large project•• Must be keep up to dateMust be keep up to date•• Does not indicate the relationships among the activitiesDoes not indicate the relationships among the activities

Project Network in Developing Project PlanProject Network in Developing Project Plan

•• The Project Network is a The Project Network is a flow chart that graphically flow chart that graphically depicts the depicts the sequence, task interdependencies sequence, task interdependencies with start with start and finish times of the project job/activities.and finish times of the project job/activities.

•• Provides the basis for scheduling labor and equipmentProvides the basis for scheduling labor and equipment•• Provides an estimate of the projectProvides an estimate of the project’’s durations duration•• Provides a basis for budgeting cash flowProvides a basis for budgeting cash flow•• Highlights activities that are Highlights activities that are ““criticalcritical”” and should not be and should not be

delayeddelayed•• Help managers get and stay on planHelp managers get and stay on plan•• WBS is hierarchical, Network is sequential, emphasizing WBS is hierarchical, Network is sequential, emphasizing

interdependenciesinterdependencies

Project Networks

Avail Avail HolidaysHolidays

ArrangeArrangeFinanceFinance

DecideDecideDestinationDestination

MakeMakeBookingsBookings

TravelTravel

Contact Contact Travel AgentTravel Agent

•• Showing Interrelationship between various Showing Interrelationship between various taskstasks

•• Scheduling tasks on a time lineScheduling tasks on a time line

2 Versions of Network Diagrams2 Versions of Network DiagramsActivityActivity--onon--Arrow (AOA) networksArrow (AOA) networks

–– also called Arrow Diagramming Method (ADM)also called Arrow Diagramming Method (ADM)–– simpler for projects with many dependenciessimpler for projects with many dependencies–– emphasizes events; milestones can be easily flaggedemphasizes events; milestones can be easily flagged–– sometimes requires dummy activitiessometimes requires dummy activities

ActivityActivity--onon--Node (AON) networksNode (AON) networks–– also called Precedence Diagramming Method (PDM)also called Precedence Diagramming Method (PDM)–– easier to draw for simple projectseasier to draw for simple projects–– emphasizes activitiesemphasizes activities–– no dummy activitiesno dummy activities

ActivityActivity--onon--Arrow (AOA) NetworksArrow (AOA) Networksbb

cc

dd

ee

ffgg

ActivityActivity PredecessorPredecessormmnnrrss

____

m, nm, nnn

mm rr

nn ss

kk

jj

kk

jj

jj

kk

oror

Dashed lines are called Dashed lines are called dummy activitiesdummy activities

Project Network TerminologyProject Network Terminology–– Activity:Activity: an element of the project that requires time.an element of the project that requires time.

–– Merge activity:Merge activity: an activity that has two or more preceding an activity that has two or more preceding activities on which it depends.activities on which it depends.

–– Burst activity:Burst activity: an activity that has more than one activity an activity that has more than one activity immediately following it (more than one dependency arrow immediately following it (more than one dependency arrow flowing from it).flowing from it).

–– Parallel (concurrent) activities:Parallel (concurrent) activities: Activities that can Activities that can occur independently and, if desired, at the same timeoccur independently and, if desired, at the same time……or notor not

AA

CC

BB DD

BB

DD

AA CC

Project Network TerminologyProject Network Terminology–– Event:Event: a point in time when an activity is started or a point in time when an activity is started or

completed. It does not consume time.completed. It does not consume time.

–– Path:Path: a sequence of connected, dependent activities.a sequence of connected, dependent activities.

–– Critical path:Critical path:•• the longest path through the activity network that allows for ththe longest path through the activity network that allows for the e

completion of all projectcompletion of all project--related activities;related activities;

•• It is also the shortest expected time in which the entire projecIt is also the shortest expected time in which the entire project t can be completed. Delays on the critical path will delay can be completed. Delays on the critical path will delay completion of the entire project.completion of the entire project.

DD

CC

AA BB

11 22Excavate Excavate & pour & pour footingsfootings

Pour Pour foundationfoundation

Install Install drainsdrains

Project Network for Project Network for House ConstructionHouse Construction

(AOA network)(AOA network)

33

66

77

44

88

99

55

1010

1111

1212

1616

18181313

17171515

1414

Install roughInstall roughelectrical & plumbingelectrical & plumbing

PourPourbasementbasement

floorfloorInstallInstall

cooling &cooling &heatingheating

ErectErectframe & roofframe & roof

LayLaybrickworkbrickwork

LayLaystormstormdrainsdrains

InstallInstalldrywalldrywall

LayLayflooringflooring

InstallInstallfinishedfinished

plumbingplumbing

InstallInstallkitchenkitchen

equipmentequipmentPaintPaint

FinishFinishroofroof

InstallInstallroofroof

drainagedrainage

FinishFinishgradinggrading

FinishFinishfloorsfloors

PourPourwalks;walks;

LandscapeLandscape

FinishFinishelectricalelectrical

workwork

FinishFinishcarpetingcarpeting

–– ActivityActivity--onon--Node (AON)Node (AON)•• Uses a node to depict an activityUses a node to depict an activity•• Used in Software IndustryUsed in Software Industry

–– ActivityActivity--onon--Arrow (AOA)Arrow (AOA)•• Uses an arrow to depict an activityUses an arrow to depict an activity•• Traditional in ConstructionTraditional in Construction

Project Network RepresentationProject Network Representation

Network Computation ProcessNetwork Computation Process•• Forward PassForward Pass——Earliest TimesEarliest Times

–– How soon can the activity start? (early startHow soon can the activity start? (early start——ES)ES)–– How soon can the activity finish? (early finishHow soon can the activity finish? (early finish——EF)EF)–– How soon can the project finish? (expected timeHow soon can the project finish? (expected time——ET)ET)

•• Backward PassBackward Pass——Latest TimesLatest Times–– How late can the activity start? (late startHow late can the activity start? (late start——LS)LS)–– How late can the activity finish? (late finishHow late can the activity finish? (late finish——LF)LF)–– Which activities represent the critical path?Which activities represent the critical path?–– How long can it be delayed? (slack or floatHow long can it be delayed? (slack or float——SL)SL)

Rules for drawing networksRules for drawing networks•• Networks flow from left to rightNetworks flow from left to right•• A task cannot begin until all immediate predecessors have been A task cannot begin until all immediate predecessors have been

completedcompleted•• Arrows on networks indicate precedence and flow and arrows can Arrows on networks indicate precedence and flow and arrows can

cross over each othercross over each other•• Each task should have a unique identification (ID) numberEach task should have a unique identification (ID) number•• A task identification number must be larger than any tasks that A task identification number must be larger than any tasks that precede precede

it (topological order)it (topological order)•• Looping is not allowedLooping is not allowed•• Conditional statements are not allowedConditional statements are not allowed•• When multiple tasks commence the project, create a common When multiple tasks commence the project, create a common ““Project Project

StartStart”” task, and similarly, a common task, and similarly, a common ““Project EndProject End”” task to indicate a task to indicate a clear terminationclear termination

ManagerManager’’s View of CPMs View of CPM

INPUTS INPUTS •• List of project activitiesList of project activities•• Precedence relationship among activitiesPrecedence relationship among activities•• Estimate of each activityEstimate of each activity’’s durations duration

OUTPUTS • Estimated duration of project• Identification of critical activities• Amount of slack for each activity

CPM processing procedures

Critical Path Method (CPM)Critical Path Method (CPM)

•• CPM is a project network analysis technique used to predict CPM is a project network analysis technique used to predict

total project durationtotal project duration

•• A critical path for a project is the series of activities that A critical path for a project is the series of activities that

determines the determines the earliest time earliest time by which the project can be by which the project can be

completedcompleted

•• The critical path is the The critical path is the longest path longest path through the network through the network

diagram and has the zero slack or floatdiagram and has the zero slack or float

Steps in CPM AnalysisSteps in CPM Analysis•• Draw the CPM networkDraw the CPM network

–– A graphic view of the relationships among the A graphic view of the relationships among the required activitiesrequired activities

•• Analyze the paths through the networkAnalyze the paths through the network–– Determine the length of each path (the time required Determine the length of each path (the time required

to complete each path) to complete each path) –– Starting at the beginning of the network and working Starting at the beginning of the network and working

toward the end (from left to right), determine the ES toward the end (from left to right), determine the ES and the EF for each activityand the EF for each activity

–– Identify the critical path(s) (the longest path[s] Identify the critical path(s) (the longest path[s] through the network)through the network)

Slacks in CPM AnalysisSlacks in CPM Analysis•• Free slack or free float Free slack or free float is the amount of time an is the amount of time an

activity can be delayed without delaying the early activity can be delayed without delaying the early

start of any immediately following activities [ES of start of any immediately following activities [ES of

following activityfollowing activity--EF of the activity]EF of the activity]

–– Tends to happen as the last activity in a path before a merge Tends to happen as the last activity in a path before a merge

activity (when another path is the critical one).activity (when another path is the critical one).

•• Total slack or total float Total slack or total float is the amount of time an is the amount of time an

activity may be delayed from its early start without activity may be delayed from its early start without

delaying the planned project finish date [LSdelaying the planned project finish date [LS--ES]ES]

Steps in CPM AnalysisSteps in CPM Analysis•• Determine the slack for each activityDetermine the slack for each activity

–– Working from the end of the project network (from Working from the end of the project network (from right to left), find the LF and the LS for each right to left), find the LF and the LS for each activityactivity

–– Compute the activityCompute the activity’’s slacks slackslack = LS slack = LS -- ES = LF ES = LF -- EFEF

–– Slack is the maximum amount of time that this Slack is the maximum amount of time that this activity can be delayed in its completion before it activity can be delayed in its completion before it becomes a critical activity, i.e., delays completion becomes a critical activity, i.e., delays completion of the projectof the project

CPM ExampleCPM Example•• CPM NetworkCPM Network

StartStartStart

A(6)A(6)A(6)

G(17)G(17)G(17)

C(5)C(5)C(5)

B (8)B (8)B (8) D(13)D(13)D(13)

F(15)F(15)F(15)

E(9)E(9)E(9)

H(9)H(9)H(9)

J(12)J(12)J(12)

I (6)I (6)I (6) ENDENDEND

Find Critical Path of Project & Slacks in each activityFind Critical Path of Project & Slacks in each activity

•• CPM NetworkCPM Network

StartStartStart

A(6)A(6)A(6)

G(17)G(17)G(17)

C(5)C(5)C(5)

B (8)B (8)B (8) D(13)D(13)D(13)

F(15)F(15)F(15)

E(9)E(9)E(9)

H(9)H(9)H(9)

J(12)J(12)J(12)


CPM ExampleCPM Example

•• Paths EnumeratedPaths Enumerated

PathPath Length of PathLength of Path

AA--FF--HH 6 + 15 + 9 = 306 + 15 + 9 = 30AA--GG--II 6 + 17 + 6 = 296 + 17 + 6 = 29BB--DD--JJ 8 + 13 + 12 = 33*8 + 13 + 12 = 33*CC--EE--JJ 5 + 9 + 12 = 265 + 9 + 12 = 26

* Critical path* Critical path


StartStartStart

A(6)A(6)A(6)

G(17)G(17)G(17)

C(5)C(5)C(5)

B (8)B (8)B (8) D(13)D(13)D(13)

F(15)F(15)F(15)

E(9)E(9)E(9)

H(9)H(9)H(9)

J(12)J(12)J(12)


0 6

0 8

0 5

0 0

•• ES and EF TimesES and EF Times

Forward SchedulingForward Scheduling


StartStartStart

A(6)A(6)A(6)

G(17)G(17)G(17)

C(5)C(5)C(5)

B (8)B (8)B (8) D(13)D(13)D(13)

F(15)F(15)F(15)

E(9)E(9)E(9)

H(9)H(9)H(9)

J(12)J(12)J(12)


0 6

0 8

0 5

0 0



6 21

6 23

8 21

5 14


StartStartStart

A(6)A(6)A(6)

G(17)G(17)G(17)

C(5)C(5)C(5)

B (8)B (8)B (8) D(13)D(13)D(13)

F(15)F(15)F(15)

E(9)E(9)E(9)

H(9)H(9)H(9)

J(12)J(12)J(12)


0 6

0 8

0 5

0 0



6 21

6 23

8 21

5 14

21 33

23 29

21 30


StartStartStart

A(6)A(6)A(6)

G(17)G(17)G(17)

C(5)C(5)C(5)

B (8)B (8)B (8) D(13)D(13)D(13)

F(15)F(15)F(15)

E(9)E(9)E(9)

H(9)H(9)H(9)

J(12)J(12)J(12)


0 6

0 8

0 5

0 0


Project Completion Time = 33 wksProject Completion Time = 33 wks

6 21

6 23

8 21

5 14

21 33

23 29

21 30

33 33

ProjectProject’’s EF = 33s EF = 33


StartStartStart

A(6)A(6)A(6)

G(17)G(17)G(17)

C(5)C(5)C(5)

B (8)B (8)B (8) D(13)D(13)D(13)

F(15)F(15)F(15)

E(9)E(9)E(9)

H(9)H(9)H(9)

J(12)J(12)J(12)


0 6

0 8

0 5

0 0

•• LS and LF TimesLS and LF Times


6 21

6 23

8 21

5 14

21 33

23 29

21 30

33 33

21 33

27 33

24 33


StartStartStart

A(6)A(6)A(6)

G(17)G(17)G(17)

C(5)C(5)C(5)

B (8)B (8)B (8) D(13)D(13)D(13)

F(15)F(15)F(15)

E(9)E(9)E(9)

H(9)H(9)H(9)

J(12)J(12)J(12)


0 6

0 8

0 5

0 0

•• LS and LF TimesLS and LF Times


6 21

6 23

8 21

5 14

21 33

23 29

21 30

33 33

21 33

27 33

24 339 24

10 27

8 21

12 21

3 9

0 8

7 12


StartStartStart

A(6)A(6)A(6)

G(17)G(17)G(17)

C(5)C(5)C(5)

B (8)B (8)B (8) D(13)D(13)D(13)

F(15)F(15)F(15)

E(9)E(9)E(9)

H(9)H(9)H(9)

J(12)J(12)J(12)


0 6

0 8

0 5

0 0

•• SlackSlack


6 21

6 23

8 21

5 14

21 33

23 29

21 30

33 33

21 33

27 33

24 339 24

10 27

8 21

12 21

3 9

0 8

7 12

3

0

7

0

4

3

70

4

3


StartStartStart

A(6)A(6)A(6)

G(17)G(17)G(17)

C(5)C(5)C(5)

B (8)B (8)B (8) D(13)D(13)D(13)

F(15)F(15)F(15)

E(9)E(9)E(9)

H(9)H(9)H(9)

J(12)J(12)J(12)


•• Critical pathCritical path 3

0

7

0

4

3

70

4

3

More on the Critical PathMore on the Critical Path

•• If one or more activities on the critical path takes If one or more activities on the critical path takes longer than planned, the whole project schedule will longer than planned, the whole project schedule will slip slip unlessunless corrective action is takencorrective action is taken

•• Misconceptions:Misconceptions:–– The critical path is not the one with all the critical activitieThe critical path is not the one with all the critical activities; it s; it

only accounts for time.only accounts for time.–– There can be more than one critical path if the lengths of two There can be more than one critical path if the lengths of two

or more paths are the sameor more paths are the same–– The critical path can change as the project progressesThe critical path can change as the project progresses

Techniques for Shortening a Project ScheduleTechniques for Shortening a Project Schedule

Shorten durations of critical tasks by adding more Shorten durations of critical tasks by adding more

resources or changing their scoperesources or changing their scope

•• Fast tracking Fast tracking tasks by doing them in parallel or overlapping tasks by doing them in parallel or overlapping

them.them.

•• Crashing Crashing tasks by obtaining the greatest amount of tasks by obtaining the greatest amount of

schedule compression for the least incremental costschedule compression for the least incremental cost

•• Critical Chain ApproachCritical Chain Approach

Crashing and Fast TrackingCrashing and Fast Tracking

OverlappedTasks or fasttracking

Shortenedduration thrucrashing

Original schedule

Another Way to Find SlackAnother Way to Find Slack--The Gantt ChartThe Gantt Chart

•• Once activity precedence and durations are established, Once activity precedence and durations are established, we can determine the critical path and slack via a Gantt we can determine the critical path and slack via a Gantt chart.chart.

•• Gantt charts can be handGantt charts can be hand--drawn, but practitioners drawn, but practitioners generally use MSgenerally use MS--ProjectProject..

Sensitivity of a NetworkSensitivity of a Network

•• Defined as the likelihood the original critical Defined as the likelihood the original critical path(s) will change once the project is path(s) will change once the project is initiated.initiated.–– It is a function of:It is a function of:

•• The number of critical pathsThe number of critical paths•• The amount of slack across near critical The amount of slack across near critical

activitiesactivities

But..But..

•• UncertaintyUncertainty

Program Evaluation Program Evaluation and Review Technique (PERT)and Review Technique (PERT)

•• The technique is based on the assumption The technique is based on the assumption that an activitythat an activity’’s duration follows a probability s duration follows a probability distribution instead of being a single distribution instead of being a single deterministic value.deterministic value.

•• The probabilistic information about the The probabilistic information about the activities is translated into probabilistic activities is translated into probabilistic information about the project.information about the project.

PERTPERT

•• Three time estimates are required to compute Three time estimates are required to compute the parameters of an activitythe parameters of an activity’’s duration s duration distribution:distribution:–– pessimistic timepessimistic time (t(tp p )) -- the time the activity would the time the activity would

take if things did not go welltake if things did not go well–– most likely timemost likely time (t(tm m )) -- the consensus best estimate the consensus best estimate

of the activityof the activity’’s durations duration–– optimistic timeoptimistic time (t(to o )) -- the time the activity would the time the activity would

take if things did go welltake if things did go well

••

•• From these three time estimates about an From these three time estimates about an activity, two probability distribution activity, two probability distribution parameters are calculated: the mean time parameters are calculated: the mean time estimate (testimate (te e ) and the variance (V) and the variance (Vt t ).).

ttee = ( t= ( too + 4t+ 4tmm + t+ tp p ) / 6) / 6

VVtt = [ ( t= [ ( tpp -- tto o ) / 6 ] ) / 6 ] 22

PERTPERT

Standard PERT AssumptionsStandard PERT Assumptions

1.1. The activities are independentThe activities are independent

2.2. The critical path contains a large no. of activities so that weThe critical path contains a large no. of activities so that we

can invoke the Central Limit Theorem.can invoke the Central Limit Theorem.

3.3. Activity times follow a Beta distribution.Activity times follow a Beta distribution.

PERT ProcedurePERT Procedure

•• Compute mean and variance of all jobs.Compute mean and variance of all jobs.

•• Conduct forward and backward pass on the project network Conduct forward and backward pass on the project network with expected times of all activities.with expected times of all activities.

•• Identify the Critical Path.Identify the Critical Path.

•• Obtain variance of critical path by adding variance of activitiObtain variance of critical path by adding variance of activities.es.

•• Obtain the distribution of the Project Duration.Obtain the distribution of the Project Duration.

•• Make probability statements about the project Make probability statements about the project –– Chances of meeting the target date.Chances of meeting the target date.

–– Probability of exceeding a given ceiling date.Probability of exceeding a given ceiling date.

–– Probability that the project duration is confined to an intervalProbability that the project duration is confined to an interval of timeof time..

Steps in PERT AnalysisSteps in PERT Analysis

•• Draw the network.Draw the network.•• Analyze the paths through the network and Analyze the paths through the network and

find the critical path.find the critical path.•• The length of the critical path is the mean of The length of the critical path is the mean of

the project duration probability distribution the project duration probability distribution which is assumed to be normal.which is assumed to be normal.

Steps in PERT AnalysisSteps in PERT Analysis

•• The standard deviation of the project duration The standard deviation of the project duration probability distribution is computed by adding probability distribution is computed by adding the variances of the critical activities (all of the the variances of the critical activities (all of the activities that make up the critical path) and activities that make up the critical path) and taking the square root of that sumtaking the square root of that sum

•• Probability computations can now be made Probability computations can now be made using the normal distribution table.using the normal distribution table.

PERT Example PERT Example Immed. Optimistic Most Likely PessimisticImmed. Optimistic Most Likely Pessimistic

ActivityActivity Predec.Predec. Time (Hr.Time (Hr.) ) Time (Hr.)Time (Hr.) Time (Hr.)Time (Hr.)A A ---- 4 6 84 6 8B B ---- 1 4.5 51 4.5 5C A 3 3 C A 3 3 33D A 4 5 D A 4 5 6 6 E A 0.5 1 E A 0.5 1 1.51.5F B,C 3 4 F B,C 3 4 55G B,C 1 1.5 G B,C 1 1.5 55H E,F 5 6 H E,F 5 6 77I E,F 2 5 I E,F 2 5 88J D,H 2.5 2.75 J D,H 2.5 2.75 4.54.5K G,I 3 5 K G,I 3 5 77

PERT ExamplePERT Example

JJJAAA

DDD

BBB

StartStartStart

KKK

CCC

GGG

FFF

EEE

III

HHH

FinishFinishFinish

PERT ExamplePERT Example•• Activity Expected Time and Variance Activity Expected Time and Variance

ActivityActivity Expected TimeExpected Time VarianceVarianceA A 6 6 4/94/9B B 4 4 4/94/9C C 3 3 00D D 5 5 1/91/9E E 1 1 1/361/36F F 4 4 1/91/9G G 2 2 4/94/9H H 6 6 1/91/9I I 5 5 11J J 3 3 1/91/9K K 5 5 4/94/9

PERT ExamplePERT Example•• Earliest/Latest TimesEarliest/Latest Times

ActivityActivity ESES EFEF LSLS LFLF SlackSlackA 0 A 0 6 6 0 0 6 6 00 *critical*criticalB 0 B 0 4 4 5 5 9 9 55C 6 C 6 9 9 6 6 9 9 0 *0 *D 6 D 6 11 11 15 15 20 20 99E 6 E 6 7 7 12 12 13 13 66F 9 F 9 13 13 9 9 13 13 0 *0 *G 9 G 9 11 11 16 16 18 18 77H H 13 13 19 19 14 14 20 20 11I I 13 13 18 18 13 13 18 18 0 *0 *J J 19 19 22 22 20 20 23 23 11K K 18 18 23 23 18 18 23 23 0 *0 *

PERT ExamplePERT Example•• Probability the project will be completed within Probability the project will be completed within

24 hours24 hoursVVpathpath = V= VAA + V+ VCC + V+ VFF + V+ VII + V+ VKK

= 4/9 + 0 + 1/9 + 1 + 4/9 = 4/9 + 0 + 1/9 + 1 + 4/9 = 2= 2

σσpathpath = 1.414= 1.414

zz = (24 = (24 -- 23)/23)/σ = σ = (24(24--23)/1.414 = .7123)/1.414 = .71

PERT ExamplePERT Example•• Probability the project will be completed Probability the project will be completed

within 24 hourswithin 24 hours

2323 2424



2323 2424

0 0 0.710.71



From the Standard Normal Distribution table: From the Standard Normal Distribution table:

P(z P(z << .71) = .5 + .2612 = .7612.71) = .5 + .2612 = .7612

2323 2424

.5000.5000

.2612.2612 0 0 0.710.71

0.26120.2612

ActivitiesID Activity Duration Predecessor1 Market Analysis 25

2 Product Design 40 1

3 Manufacturing Study 20 1

4 Product Design Selection 10 2,3

5 Detailed Marketing Plan 15 4

6 Manufacturing Process 30 4

7 Detailed Product Design 50 4

8 Test Prototype 10 7

9 Finalized Product design 25 6,8

10 Order Components 7 9

11 Order Production equipment 14 9

12 Install production equipment 25 10,11

13 Celebrate 1 12

Class ExerciseClass Exercise--11

Rules for drawing networks•• Networks flow from left to rightNetworks flow from left to right•• A task cannot begin until all immediate predecessors have been A task cannot begin until all immediate predecessors have been

completedcompleted•• Arrows on networks indicate precedence and flow and arrows can cArrows on networks indicate precedence and flow and arrows can cross ross

over each otherover each other•• Each task should have a unique identification (ID) numberEach task should have a unique identification (ID) number•• A task identification number must be larger than any tasks that A task identification number must be larger than any tasks that

precede it (topological order)precede it (topological order)•• Looping is not allowedLooping is not allowed•• Conditional statements are not allowedConditional statements are not allowed•• When multiple tasks commence the project, create a common When multiple tasks commence the project, create a common ““Project Project

StartStart”” task, and similarly, a common task, and similarly, a common ““Project EndProject End”” task to indicate a task to indicate a clear terminationclear termination

•• What is the completion time of the project, What is the completion time of the project, activities? Which are critical activitiesactivities? Which are critical activities

11

2525

33

2020

44

1010

22

4040

55

1515

66

3030

77

5050

99

2525

88

1010

1111

1414

1010

77

1212

2525

1313

11

200200 1414

00

200200

00 11

2525

2525

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2020

4545

6565 44

1010

7575

2525 22

4040

6565

7575 55

1515

9090

7575 66

3030

101055

7575 77

5050

121255

131355 99

2525

161600

121255 88

1010

131355

161600

1111

1414

171744

161600

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77

161677

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1212

2525

191999

199199 1313

11

200200

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00

200200

00 11

00 2525

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4545 2020

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6565

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7575

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2525 22

2525 4040

6565

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185185 1515

9090

200200

7575 66

101055

3030

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131355

7575 77

7575 5050

121255

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131355 99

131355

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161600

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131355

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1111

161600

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171744

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161677 77

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1212

171744

2525

191999

191999

199199 1313

199199 11

200200

200200

200200 1414

200200 00

200200

200200

•• Critical Activities : 1Critical Activities : 1--22--44--77--88--99--1111--1212

00 11

00 2525

2525

002525

2525 33

4545 2020

4545

2020

6565

6565 44

6565 1010

7575

7575

2525 22

2525 4040

6565

006565

7575 55

185185 1515

9090

110110

200200

7575 66

101055

3030

101055

3030

131355

7575 77

7575 5050

121255

121255

131355 99

131355

2525

161600

161600

121255 88

121255

1010

131355

131355

161600

1111

161600

1414

171744

171744

161600

1010

161677 77

16167777

171744

171744

1212

171744

2525

191999

191999

199199 1313

199199 11

200200

200200

200200 1414

200200 00

200200

00200200

00

00 00

00

00

00

00

EXTENSIONS TO PERT/CPMEXTENSIONS TO PERT/CPM

Precedence DiagrammingPrecedence Diagramming

•• FinishFinish--toto--start linkagestart linkage•• StartStart--toto--start linkagestart linkage•• FinishFinish--toto--finish linkagefinish linkage•• StartStart--toto--finish linkagefinish linkage

Task Dependency TypesTask Dependency Types

Precedence Diagramming ConventionsPrecedence Diagramming Conventions

Other MethodsOther Methods

•• Graphical Evaluation and Review Technique Graphical Evaluation and Review Technique (GERT)(GERT)–– combines flowgraphs, probabilistic networks, and combines flowgraphs, probabilistic networks, and

decision treesdecision trees–– allows loops back to earlier events and allows loops back to earlier events and

probabilistic branching probabilistic branching

New Product New Product Development Development

ProcessProcess

The Five Secrets of Project SchedulingThe Five Secrets of Project Scheduling

1.1. Create deliverablesCreate deliverables--based project schedulesbased project schedules

2.2. Determine the appropriate level of detail Determine the appropriate level of detail

3.3. Implement a regular status update and Implement a regular status update and reporting processreporting process

4.4. Review and adjust the schedule regularlyReview and adjust the schedule regularly

5.5. Create and follow project scheduling standardsCreate and follow project scheduling standards

Things to Think About When Making Things to Think About When Making Your Project PlanYour Project Plan

•• No Project Ever Runs To PlanNo Project Ever Runs To Plan•• Leave Slack (Spare Time) In Your PlanLeave Slack (Spare Time) In Your Plan

–– DonDon’’t Plan To Work 20 Hour Days t Plan To Work 20 Hour Days –– You WonYou Won’’tt–– Plan For Suppliers To Let You DownPlan For Suppliers To Let You Down–– Plan For Things To Go Wrong Plan For Things To Go Wrong –– Additional Laboratory TimeAdditional Laboratory Time–– Plan To Finish EarlyPlan To Finish Early

•• Track Your Progress Against Your PlanTrack Your Progress Against Your Plan•• If You Are Going Off Track Apply RemediesIf You Are Going Off Track Apply Remedies

–– Increase Work Rate!!Increase Work Rate!!–– Chase DelaysChase Delays–– Modify Your Plans To Accommodate The Difficulty Modify Your Plans To Accommodate The Difficulty

NOTE NOTE –– IGNORING A PROBLEM WONIGNORING A PROBLEM WON’’T MAKE IT GO AWAYT MAKE IT GO AWAY

1-74

The Main Reason For FailureThe Main Reason For Failure

You DidnYou Didn’’t Start Soon Enought Start Soon Enough

QuestionsQuestions

5 developing a project plan-ii

Documents