[530]4 time planning

8/8/2019 [530]4 Time Planning

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Engineering

Project Management

By

Sami Fahmy, Ph.D, P. Eng, PMP

ENG M 530 - Lecture No. 4

Planning Time (Scheduling)


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References

Project Management Book ofknowledge(PMBoK-2004). Published by

PMI

Construction Project Scheduling andControl. By Dr. Saleh Mubarak. Published

by Pearson, Prentice hall


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Agenda

1. Activity Definition

2. Activity Sequencing

3. Activity Resource Estimating

4. Activity Duration Estimating

5. Schedule Development


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Schedule is an Important Tool

1. Quantifies the time objective

2. Determines sequence and time frame for

activity accomplishment3. Establishes basis for progress evaluation

4. Allows Project Manager to make educateddecisions

5. Define significant events and activities for

the project6. Allows for the control of project activities

(Used as a baseline)


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Time Planning Processes

Primary Input Process Major Output

WBS and scope

statement

Activity Definition Activity list

Activity list

Activity Attribute

Activity Sequencing Project schedulenetwork diagram

Activity list

Activity List

Project schedule network Diagram

Activity durationestimate

Activity ResourceEstimating

Activity Duration

Estimating

Schedule

Development

Activity resourceRequirement

Activity duration

estimate

Project Schedule


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1. Activity Definition

Identifies and documents the work that isplanned to be performed

Decomposes Work Packages intoactivities

Provides a basis for estimating,scheduling, execution, monitoring andcontrol

The activities scheduled must relate toprojects objectives


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1. Activity Definition Process

Project ScopeStatement

WBS

Activity List

Activity Attributes

Milestone List

Tools and Techniques

1. Decomposition

2. Templates

3. Rolling wave

planning4. Expert

judgment

5. Planningcomponent


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1. Activity Definitions (T & T)

Decomposition Subdividing the project work

package into smaller scheduledactivities

Activities (action statements)

Major outputs are described asactivities

Decomposition is done bymembers responsible for workpackages


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1. Activity Definitions (T & T)

Templates Activity lists from previous projects are

often used Advantages and disadvantages

Also consider activity attributes. Arethey valid for this project?

It identifies typical milestones for atypical project


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1. Activity Definitions (Outputs)

Activity List

Include all activities Describe each activity in detail

Organized as an extension to WBS


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Activity Attributes Used for planning schedule activities

and schedule development Examples:

Activities identifier/description

Activity codes

Logical relationships

Resource requirements Imposed dates

Constraints and assumptions


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Milestone list

Identifies milestones Mandatory or optional

Part of the project management plan


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2. Activity Sequencing

Identifying and documenting interactivity

dependencies Accurately sequencing project activities

will contribute to a realistic and achievable

schedule Use manual or computer program in

sequencing activities, or a combination ofboth


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2. Activity Sequencing Process

Tools and techniques

1. PrecedenceProgramming Method(PDM or AON)

2. Arrow Diagramming

Method (ADM/AOA)

3. Schedule networktemplates

4. Dependencydetermination

5. Applying leads andlags

Project Scope Statement

Activity list

Activity attributes

Milestone list

Approved change requests

Project Schedule

Network Diagrams

Activity list (updates)

Activity attributes(updates)

Requested changes

2 A i i S i (T & T)


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2. Activity Sequencing (T & T)

Precedence Programming Method (PDM)

Project network diagram with:

Nodes representing activities

Arrows representing dependencies

Used by most project management software No dummy activities

Activity Constraint Activity

2 A ti it S i (T & T)


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Also called Activity on Node Method(AON)

Event oriented

Activities represented by nodes

Arrow denotes the precedence

relationship



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Start

Activity A Activity B

Activity C Activity D

Finish



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Arrow Diagramming Method (ADM) Network diagramming with:

Arrows representing activities Nodes representing dependencies

It only allows finish to startdependencies

Event Activity Event

2 Activity Sequencing (T & T)


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Arrow Diagramming Method (ADM)

Also called Activity on Activity Method (AON) Work done between two events is an activity

Activity (arrow) connects two events

Activity oriented

The succeeding activity could NOT start until

preceding activity is completed Finish to Start relationship

Dummy activities used to indicate

interdependency



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Arrow Diagramming Method (ADM)

Start FinishA

BC

F

E

D Dum

my

Activity



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Dummy Activity An activity of zero duration

Used to show logical relationship(dependencies)

Shown as a dashed line headed by anarrow

Indicate interdependency

Know the Difference:


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Know the Difference:

AOA:

pour (1 d) cure (7 d) install

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concrete walls concrete floor joist

AON:

pour concrete Lag (7 d) install floorwall joist

Types of Relationships


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Finish to Start

Start to Start

Finish to Finish

Start to Finish (Not used often)

Types of Dependencies


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Types of Dependencies

Finish to Start Relationship (FS)

AOA PDM

Running wires can NOT

start until framing is finished

FrameWall

RunWire Frame

WallRunWire



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AOA PDM

Start to Start Relationship (SS)

Begin wall

framing

Complete wall

framing

Runwiring

Frame

walls

Run

wires

Wiring can NOT start until

wall framing starts



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AOA PDM

Finish to Finish Relationship

Install

shingles

Begin roof Complete roof

Install

shingles

Roof

Roofing can NOT be finished

until the shingles are finished

Know the Difference


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Know the Difference

PDM (AON)

Shows

interdependenciesNo dummy activities arerequired

New activities can beeasily added to schedule

More flexible

Utilizes lags betweenactivities

ADM (AOA)

Show

interdependency

Dummy activities can

be usedNo lags between

activities



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Dependency

Indicates the relationship betweenactivities or tasks

Mandatory

Discretionary

External



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Mandatory Dependencies (Hard Logic) They are inherent in the nature of the

work being done.

They include physical limitations:

Build a basement before starting

the superstructure Build prototype before testing starts

Write Review

Document document



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Discretionary Dependencies (Soft Logic) Defined by the project management

team

soft logic or preferential logic/preferredlogic

Use with care and document, may limitscheduling options

Based on: Best practices of a particular industry

Desired specific sequencing



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External Dependencies Activities that involve a relationship

between project activities and non-project activities

Examples:

Environmental hearing before sitepreparation work begins

Delivery of a product has to be donebefore on-site testing may begin

2. Activity Sequencing (Outputs)


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Project Schedule Network Diagrams Activity list (updates)



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Project Schedule Network Diagrams A schematic display of the projects

activities and the logical relationshipamong them

The diagram should be accompaniedby:

Summary of the basic sequencing

approach

Details of any unusual sequencing



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1. Expert judgment

2. Alternatives analysis

3. Published estimatingdata

4. Project management

software

5. Bottom-up estimating

Activity list

Activity attributes

Resource availability

Activity resource

requirements

Activity attributes

(updates)

Resource breakdown

structure

3 Activity Resource Estimating (T & T)


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3. Activity Resource Estimating (T & T)

Published estimating data

Production rates

Unit cost

Hourly rate

Etc.

3. Activity Resource Estimating (T & T)


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y g ( )

Bottom-up estimating

Engineering estimate

Most accurate estimate

Uses WBS

Advantages and disadvantages

3 Activity Resource Estimating (Outputs)


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3. Activity Resource Estimating (Outputs)

Activity resource requirements

Resource breakdown structure

Activity Resource Estimating (Outputs)


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y g ( p )

Activity Resource Requirements Resources assigned to project will

significantly influence the duration of theactivities

Doubling the number of resourcesassigned to a project may or may beable to complete the tasks in half the

time Watch for efficiency,safety and space

limitation

Activity Resource Estimating (Outputs)


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y g p

Resource Breakdown Structure Hierarchal structure

Identifies resources by: Category

Type



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The process of taking information onthe project scope and resources

and then developing durations for

input to schedule



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Involves estimating the number of workperiods likely to be needed to completeeach identified activity

Estimates should be approved by an

experienced person in the type of workunder consideration

Considers the elapsed time required forspecific operations



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Tools and techniques1. Expert judgment

2. Analogous

estimating3. Parametric

estimating

4. Three-point estimate

5. Reserve analysis

Project scope statement

Activity list

Activity attributes

Activity resource

requirements

Activity DurationEstimates

Activity Attributes

(updates)

Activity Duration Estimating (Inputs)


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Project scope statement

Activity list

Activity attributes


Activity Duration Estimating Guidelines


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Estimate each activity independently Assume a normal level of labour and

equipment

Assume a normal work week

Disregard any predetermined contract

completion date Use past experience as a guide

Use consistent time unit

Activity Duration Estimating (T & T)


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Analogous estimating

Parametric estimating Three-point estimate



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Analogous Estimating (Top down) Using actual estimate from a previous,

similar activity as a basis for estimatingother activity

A Form of expert judgment

Most reliable when:

The previous activity is similar

The individual preparing the estimatehas the needed expertise



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Parametric Estimating (quantitative) Uses mathematical models

Regression analysis Scatter diagram

Learning curves Activity duration = quantity x unit

rate



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Three-Point Estimate Use three-point estimate for each

activity: Most likely (Realistic)

Optimistic (Best-case scenario) Pessimistic (Worst-case scenario)

Examples

Activity Duration Estimating (Outputs)


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Activity Duration Estimates

Activity Attributes (updates)

4. Activity Duration Estimating (Outputs)


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Activity Duration Estimates

Quantitative assessments of the likely

number of work periods that will berequired to complete an activity

Indicate a range to give some idea ofaccuracy

E.g.. 10 days 2 days (8-12 days) 15% probability of exceeding the 10

days

5. Schedule Development


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Schedule development is concerned with:

Determine start and finish for each

activity Determine the critical path

Must be realistic Iterative approach

5. Schedule Development Process


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1. Schedule networkanalysis

2. Critical path method

Activity list

Activity attributes

schedule network diagrams


Activity duration estimates

Project schedule

Schedule model

data

Schedule baseline

Resource requirements

(updates)

5. Schedule Development (Inputs)


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Activity list

Activity attributes Project schedule network diagrams

Activity resource requirements Activity duration estimates

Risk register

5. Schedule Development (T & T)


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Schedule network analysis

Critical path method

Schedule compression

Resource leveling

Project management software



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Schedule network analysis Analytical techniques

Involves calculating theoretical earlyand late starts and finish dates for allproject activities, regardless of any

resource pool description

The resulting information is not the

schedule but an indication of theschedule



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Calculates a single deterministic

early and late start and finish. Basedon single duration estimate

The focus of the schedule is on thecalculation of the float



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The longest path through a networkdiagram

Determines the date for earliest

completion of the project Series of activities that has (no float)

Questions on CPM


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Can a critical path change? If yes, when? Is it possible to have more than one critical

path?

Is it a good idea to have 2 paths? The latest finish time for activities A, B, and C

is 10, 15, 16. What is the earliest start time for

activity D?

D

A

BC

Questions on CPM (contd)


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The latest start time for activity A, B, C is 10, 15,16. What is the latest finish time for Activity D?

Activity A, early start is 5 weeks and latest startis 6 weeks. This activity has to be delayed by 1week as a result of last equipment delivery. What

is the effect on the critical path?

D

A

B

C

A

Float


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Slack time

Built-in time flexibility

Critical activities has no float

Any delay in the critical activities willresult in the delay of the project

Float can be positive or negative

Two Types of Float


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Free float

The amount of time an activity can

be delayed without delaying theearly start date of its successor

activityTotal float

The amount of time a task can bedelayed without delaying theprojects completion date

5. Schedule Development (Outputs)


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Project Schedule

Formats

Project Schedule Networkdiagram

Bar Chart (Gantt chart) Milestone chart

Bar Chart


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Advantages Good, fast and

easy

Easy to update

Shows plan and

schedule Excellent tool for

small projects

Good reportingtool

Disadvantages No critical path

No dependency

Milestone Chart


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Shows the following: Critical activities duration

Critical path in a very simple form Dates of major deliverables and key

events

Activity dependencies

5. Schedule Development (Outputs)


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Schedule Baseline

Once completed, it will be used for:

Basis for performance measurement

Basis for corrective action

Basis for schedule forecasts

[530]4 time planning

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