Process Improvement - Lecture Notes | CEN 5035, Study notes of Software Engineering

Download Process Improvement - Lecture Notes | CEN 5035 and more Study notes Software Engineering in PDF only on Docsity!

Chapter 28Chapter

Process Improvement

©Ian Sommerville 2004

Software Engineering. Chapter 28

Objectives^ z

To explain the

principles of software process

Objectives^ z

To

explain the principles of software process

improvement

z

To explain how process factors influence

z

To explain how process factors influence quality

and

productivity

z

To explain the notion of

process capability

z

To

explain the notion of process capability

and the CMMI process improvement model ©Ian Sommerville 2004

Software Engineering. Chapter 28

Topics covered^ z

Process attributes

Topics

covered

z

Process

attributes

z

The process improvement cycleProcess and product quality

z

Process

and product quality

z

The SEI’s CMMI framework (Read chapter introduction + sections 28.

and 28 6)and 28.6)

©Ian Sommerville 2004

Software Engineering. Chapter 28

Process attributes^ z

Most process improvement work has

Process

attributes

z

Most

process improvement work has

focused on (product) defect reduction.(This reflects the increasing attention paidb

i d

t^

t^

lit

i^

th

l

by industry to quality since the early’80’s.)

z

However

process attributes

themselves

z

However,

process

attributes

themselves

can also be the focus of improvement… ©Ian Sommerville 2004

Software Engineering. Chapter 28

Process attributes (cont’d)Process

attributes (cont’d)

Reliability:

Can

process

errors

be avoided or trapped

Reliability:

Can

process

errors

be

avoided or trapped

before they result in

product

errors

?

Robustness:

Can the process continue despite

unexpected problems?

Maintainability:

Can the process

evolve

to reflect

changing organizational requirements or to makechanging organizational requirements or to makeprocess improvements?

Rapidity:

How fast can the process be completed?

©Ian Sommerville 2004

Software Engineering. Chapter 28

Topics covered^ z

Process attributes

Topics

covered

z

Process

attributes

z

The process improvement cycleProcess and product quality

z

Process

and product quality

z

The SEI’s CMMI framework ©Ian Sommerville 2004

Software Engineering. Chapter 28

Process improvement stages

z

Process

measurement

Process improvement stages

ƒ

Attributes of the current process aremeasured. (Provides a baseline forassessing improvements )assessing improvements.)

z

Process

analysis

ƒ

Bottlenecks and weaknesses are identified.

ƒ

Changes aimed at improving measures areidentified.

Process

change

z

Process

change

ƒ

Changes are introduced.

©Ian Sommerville 2004

Software Engineering. Chapter 28

Topics covered^ z

Process attributes

Topics

covered

z

Process

attributes

z

The process improvement cycleProcess and product quality

z

Process

and product quality

z

The SEI’s CMMI framework ©Ian Sommerville 2004

Software Engineering. Chapter 28

P i

i

l

d

t

lit

f

t

P

rincipal product quality factors

(tool support)(tool

support)

©Ian Sommerville 2004

Software Engineering. Chapter 28

M

lit

li

ti

M

ore quality generalizations…

z

For

large projects with

“average” people

z

For

large

projects with

average

people

capabilities,

process determines product

quality.

z

For

small projects…

ƒ

people capabilities

tend to be more

important; butimportant; but

ƒ

development technology

(tool support) is

also important.

z

In

all

cases,

an unrealistic schedule can

cause product quality to suffer. ©Ian Sommerville 2004

Software Engineering. Chapter 28

S

ft

E

i

i^

I

tit

t

(SEI)

S

oftware Engineering Institute (SEI)

z

DoD

-funded organization established in

z

DoD funded organization established in1984 at CMU to assess and improve thecapabilities of the US software industry.

z

Developed the influential 5-level “SoftwareCapability Maturity Model” (CMM) in early’90’s90 s.^ ƒ

To assess extent to which an organization’sprocesses follow best practices.

ƒ

Others have extended or adapted the model(e.g., SPICE, Bootstrap) for use in a widerrange of companies.

©Ian Sommerville 2004

Software Engineering. Chapter 28

g

p

SEI S

ft

CMM

t

it

l^

l

Initial

:^

essentially

uncontrolled

SEI

Software CMM maturity levels

Initial

:^

essentially

uncontrolled

Repeatable

:^

product

management procedures

defined and useddefined and used

Defined

:^

process

management procedures and

strategies defined and used

Managed

:^

quality

management strategies

defined and used

Optimizing

:^

process

improvement

strategies

defined and used ©Ian Sommerville 2004

Software Engineering. Chapter 28

Software Engineering Institute (SEI)(

t’d)

(cont’d)^ z

This

caused confusion

especially when

z

This

caused

confusion

, especially when

using more than one model at a time.

z

They were

difficult to integrate

into a

z

They were

difficult

to integrate

into

a

combined improvement program.

z

Also difficult to use in supplier selection and

z

Also difficult to use in supplier selection andsub-contracting. ©Ian Sommerville 2004

Software Engineering. Chapter 28

The CMM

I

project

The

CMMI project

z

The

C

apability

M

aturity

M

odel

I

ntegration

z

The

C

apability

M

aturity

M

odel

I

ntegration

(CMMI) project was begun in 2001 to:^ ƒ

build an initial set of

integrated

models

build

an initial set of

integrated

models

ƒ

improve best practices from existing CMMmodels

ƒ

establish a framework to enable integration offuture models

ƒ

create an associated set of appraisal and

ƒ

create an associated set of appraisal andtraining products

©Ian Sommerville 2004

Software Engineering. Chapter 28