Lecture Slides on Project Management | CS A351, Study notes of Computer Science

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Project Management

Chapters 3-

Can you develop this?

Basic Definitions: Project and

Project Plan

• Software Project:
  • All technical and managerial activities required to deliver the

deliverables to the client.

• A software project has a specific duration, consumes resources

and produces work products.

• Management categories to complete a software project:
  • Tasks, Activities, Functions
• Software Project Management Plan:
• The controlling document for a software project.
• Specifies the technical and managerial approaches to develop the

software product.

• Companion document to requirements analysis document:
  • Changes in either document may imply changes in the other document.
• The SPMP may be part of the project agreement.

Components of a Project

Project

Work Product Schedule Task Participant

Capability Maturity Model

• Model produced by the Software Engineering Institute to rate

an organization’s software development process

• Level 1: Initial - Lowest level, chaotic
• Level 2: Repeatable – Project tracking of costs, schedule, and

functionality. Able to repeat earlier successes.

• Level 3: Defined – A documented and standardized software

process. All development accomplished using the standard

processes.

• Level 4: Managed – Quantitatively manages the process and

products.

• Level 5: Optimizing – Uses the quantitative information to

continuously improve and manage the software process.

Personal Software Process

• Can use the CMM idea and apply it to an

individual software developer. Watts Humphrey developed PSP in 1997.

• Use personal time logs to measure productivity; errors timed and recorded

Date Start Stop Delta Interrupt Task 1/1 09:00 15:30 360 30 lunch 50 LOC 1/3 09:00 14:00 270 30 lunch 60 LOC 1/4 09:00 11:30 150 50 LOC 1/5 12:00 02:00 120 Testing

900 minutes to write/test a program of 160 LOC. Assuming 5 hrs/day this is 3 days to write/test 160 LOC. Productivity = 53 LOC/day

Earned Value Analysis

• Basic measures to calculate how much has

been accomplished

• Percent of the estimated time that has been completed
• Basic Measures
• Budgeted Cost of Work (BCW)
• The estimated effort for each work task
• Budgeted Cost of Work Scheduled (BCWS)
• The sum of the estimated effort for each work task that was

scheduled to be completed by the specified time

• Budget at Completion (BAC)
  • The total of the BCWS and thus the estimate of the total

effort of the project

Earned Value Analysis

• Basic Measures
  • Planned Value (PV)
    • PV = BCW/BAC
    • The percentage of the total estimated effort assigned to a

particular work task

• Budgeted Cost of Work Performed (BCWP)
  • The sum of the estimated efforts for the work tasks

completed by the specified time

• Actual Cost of Work Performed (ACWP)
  • Sum of the actual efforts for the work tasks that have been

computed

Earned Value Analysis Example

Task Estimated Effort (days)

Actual Effort To Date

Estimated Completion

Actual Completion 1 5 10 1/25 2/ 2 25 20 2/15 2/ 3 120 80 5/ 4 40 50 4/15 4/ 5 60 50 7/ 6 80 70 9/

BAC = sum of estimations = 5 + 25 + 120 + H = 330 days BCWP = estimate of completed work = 5 + 25 + 40 = 70 days EV or PC = 70/330 = 21.2% BCWS = sum of estimates scheduled to be done = 5+25 = 30 SPI = BCWP/BCWS = 70/30 = 233% SV = 70 – 30 = 40 days (ahead) ACWP = sum of actual work done = 10+20+50 = 80 CPI = BCWP / ACWP = 70/80 = 87.5% CV = BCWP – ACWP = 70-80 = -10 programmer days (behind)

Today is 4/

Track Status Over Time

• Comparison of planned costs against actual costs allows the

manager to assess the health of the project

• Earned value adds the planned costs of the tasks that have been

completed

Current

Actual cost

Earned value

Planned cost

time

Time

Other Measurement Tools

• Error Tracking
  • Previously discussed, would expect error

rates to go down over time

• Postmortem Reviews
  • Assemble key people to discuss quality,

schedule, software process. Results should

not be sanitized.

Project Management Concepts

• Follow critical / best practices
• Divide and conquer approach generally taken to

decompose work into smaller, more manageable

pieces

• Key Tasks
  • Hierarchical representation of all the tasks in a project called the Work Breakdown Structure (WBS)
  • Task model or Network model
  • Mapping of the task model to the project schedule
  • Development of a Software Project Management Plan (SPMP)

Creating Work Breakdown Structures

• Two major philosophies
  • Activity-oriented decomposition ("Functional decomposition")
    • Write the book
    • Get it reviewed
    • Do the suggested changes
    • Get it published
  • Result-oriented ("Object-oriented decomposition")
    • Chapter 1
    • Chapter 2
    • Chapter 3
• Which one is best for managing? Depends on project type:
  • Development of a prototype
  • Development of a product
  • Project team consist of many unexperienced beginners
  • Project team has many experienced developers

Estimates for establishing WBS

• Establishing an WBS in terms of percentage of

total effort:

• Small project (7 person-month): at least 7% or 0.5 PM
• Medium project (300 person-month): at least 1% or 3 PMs
• Large project (7000 person-month): at least 0.2 % or 15 PMs
• (From Barry Boehm, Software Economics)

Example: Let‘s Build a House

• What are the activities that

are needed to build a

house?

Typical activities when building a house

• Surveying
• Excavation
• Request Permits
• Buy Material
• Lay foundation
• Build Outside Wall
• Install Exterior Plumbing
• Install Exterior Electrical
• Install Interior Plumbing
• Install Interior Electrical
  • Install Wallboard
  • Paint Interior
  • Install Interior Doors
  • Install Floor
  • Install Roof
  • Install Exterior Doors
  • Paint Exterior
  • Install Exterior Siding
  • Buy Pizza

Finding these activities is a brainstorming activity. It requires similar activities used during requirements analysis

From the WBS to the Dependency Graph

• The work breakdown structure does not show any temporal

dependence among the activities/tasks

• Can we excavate before getting the permit?
• How much time does the whole project need if I know the individual times? - What can be done in parallel?
• Are there any critical actitivites, that can slow down the project significantly?
• Temporal dependencies are shown in the dependency graph
• Nodes are activities
• Lines represent temporal dependencies

Building a House (Dependency Graph)

START

Request

Surveying^ Excavation Material^ Buy Founda tion Outside^ Build Wall

Install ExteriorPlumbing

Interior^ Install Plumbing

Install Exterior Electrical

Interior^ Install Electrical

Exterior^ Install Siding

Wallboard^ Install

Paint Exterior

Roofing^ Install

Install Flooring

Paint Interior

Install Interior Doors

Install Exterior Doors

FINISH

The activity "Buy Material" must Precede the activity "Lay foundation"

Lay

Map tasks onto time

• Estimate starting times and durations for each of the activities

in the dependency graph

• Compute the longest path through the graph: This is the

estimated duration of your project

PERT

• PERT = Program Evaluation and Review

Technique

• Developed in the 50s to plan the Polaris weapon

system in the USA.

• PERT allows the manager to assign optimistic,

pessimistic and most likely estimates for the span times of each activity.

• You can then compute the probability to

determine the likelihood that overall project duration will fall within specified limits.

What do we do with these diagrams?

• Compute the project duration
• Determine activities that are critical to ensure a

timely delivery

• Analyze the diagrams
  • to find ways to shorten the project duration
  • To find ways to do activities in parallel
• 2 techniques are used
  • Forward pass (determine critical paths)
  • Backward pass (determine slack time)

Definitions: Critical Path and Slack Time

• Critical path:
  • A sequence of activities that take the longest time to complete
  • The length of the critical path(s) defines how long your project will take to complete.
• Noncritical path:
  • A sequence of activities that you can delay and still finish the project in the shortest time possible.
• Slack time:
  • The maximum amount of time that you can delay an activity and still finish your project in the shortest time possible.

Example of a critical path

Activity 3 t 3 = 1

Activity 4 t 4 = 3

Activity 2 t 2 = 1

Start

t = 0

Activity 1 t 1 = 5

End

t = 0

Activity 5 = 2

Start

t = 0

Activity 1 t 1 = 5

End

t = 0

Activity t 5 = 2

Critical path in bold face

Definitions: Start and Finish Dates

• Earliest start date:
  • The earliest date you can start an activity
• Earliest finish date:
  • The earliest date you can finish an activity
• Latest start date:
  • The latest date you can start an activity and still finish the project in the shortest time.
• Latest finish date:
  • The latest date you can finish an activity and still finish the project in the shortest time.

Backward Path

Example

Activity Latest Start(LS) Latest Finish(LF)

Activity 3 tA = 1

Activity 4 tA = 3

Activity 2 t 2 = 1 Start t = 0

Activity 1 t 1 = 5

End t = 0

Activity t 5 = 2

A2 End of week 7 A3 End of week 2

A5 End of week 7

A1 End of week 5

A4 End of week 5

Activity 3 t 3 = 1

Activity 4 t 4 = 3

Activity 2 t 2 = 1

Start of week 6

Project Duration = 7

Start of week 3

Start of week 1 Start of week 7 Start of week 2

Computation of slack times

• Slack time ST of an activity A:
  • STA = LSA - ESA
  • Subtract the earliest start date from the latest start date for each

activity

Activity 3 tA = 1

Activity 4 tA = 3

Start t = 0

Activity 1 t 1 = 5 End t = 0

Activity t 5 = 2

Activity 4 t 4 = 3

Activity 2 Activity^ t 2 = 1 A A A A A

Slack time 0 1 1 1 0

Slack times on the same path influence each other.

Example: When Activity 3 is delayed by one week, activity 4 slack time

becomes zero weeks.

Example: STA4 = 3 - 2 = 1

s 1 = 0 (^) s 2 = 1

s 3 = 1 s 4 = 1 s 5 = 0

Building a House (PERT Chart)

Duration

Start Time

Slack Time

Each Activity has a start time and

an estimated duration

• Determination of total project time
• Determination of the critical path
• Determination of slack times

START

8/27/

0

0

Request Permits

8/27/

15

0

Surveying

8/27/

(^123)

Excavation

9/17/

100

Legend

8/29/

0

Buy Material

10/1/

10

0

Lay Foundation

10/15/

150

Outside^ Build Wall

11/5/

200

Install ExteriorPlumbing

12/3/

(^1210)

Interior^ Install Plumbing

12/3/

12

0

Install Exterior Electrical

12/17/

1012

Interior^ Install Electrical

12/21/

15

0

Exterior^ Install Siding

12/31/

8

12

Wallboard^ Install

1/11/

9

0

Paint Exterior

1/12/

(^125)

Roofing^ Install

1/19/

9

12

Install Flooring

1/22/

180

Paint Interior

1/22/

11

0 Install Interior Doors

2/8/

70

Install Exterior Doors

1/19/

6

15

FINISH

2/16/

0

0

0

Gantt Chart

Time (in weeks after start)

Activity 1

Activity 2

Activity 3

Activity 4

Activity 5

Easy to read