Ch26 - Process Improvement

7/25/2019 Ch26 - Process Improvement

1/50

Chapter 26 Process improvement

Process for Process Improvement

1Chapter 26 Process improvement


2/50

Topics covered

The process improvement process

Process measurement

Process analysis

Process change The CMMI process improvement framework



3/50

Process improvement

Many software companies have turned to software

process improvement as a way of enhancing the quality

of their software, reducing costs or accelerating their

development processes.

Process improvement means understanding existing

processes and changing these processes to increase

product quality andor reduce costs and development

time.



4/50

Approaches to improvement

The process maturity approach, which focuses on

improving process and pro!ect management and

introducing good software engineering practice.

The level of process maturity reflects the extent to which good

technical and management practice has "een adopted inorgani#ational software development processes.

The agile approach, which focuses on iterative

development and the reduction of overheads in the

software process. The primary characteristics of agile methods are rapid delivery of

functionality and responsiveness to changing customer

requirements.



5/50

Process and product quality

Process quality and product quality are closely

related and process improvement "enefits arise "ecause

the quality of the product depends on its development

process.

$ good process is usually required to produce a good

product.

%or manufactured goods, process is the principal quality

determinant.

%or design&"ased activities, other factors are also

involved, especially the capa"ilities of the designers.



6/50

Factors affecting software product quality



7/50

uality factors

%or large pro!ects with 'average( capa"ilities, thedevelopment process determines product quality.

%or small pro!ects, the capa"ilities of the developers is

the main determinant. The development technology is particularly significant for

small pro!ects.

In all cases, if an unrealistic schedule is imposed then

product quality will suffer.



8/50

Process improvement process

There is no such thing as an 'ideal( or 'standard( software

process that is applica"le in all organi#ations or for all

software products of a particular type.

)ou will rarely "e successful in introducing process

improvements if you simply attempt to change the process toone that is used elsewhere.

)ou must always consider the local environment and culture and

how this may "e affected "y process change proposals.

*ach company has to develop its own process

depending on its si#e, the "ackground and skills of its

staff, the type of software "eing developed, customer

and market requirements, and the company culture.



9/50

Improvement attri!utes

)ou also have to consider what aspects of the process

that you want to improve.

The goal might "e to improve software quality and so you may

wish to introduce new process activities that change the way

software is developed and tested. )ou may "e interested in improving some attri"ute of the

process itself +such as development time, decreasing defects

etc.

)ou have to evaluate and decide which process

attri"utes are the most important to your company.



10/50

Process attri!utes

Processcharacteristic

"ey issues

-nderstanda"ility To what extent is the process explicitly defined and how easy is it tounderstand the process definition

/tandardi#ation To what extent is the process "ased on a standard generic processThis may "e important for some customers who requireconformance with a set of defined process standards. To what extentis the same process used in all parts of a company

0isi"ility 1o the process activities culminate in clear results, so that theprogress of the process is externally visi"le

Measura"ility 1oes the process include data collection or other activities that allowprocess or product characteristics to "e measured

/upporta"ility To what extent can software tools "e used to support the processactivities



11/50

Process attri!utes

Processcharacteristic

"ey issues

$ccepta"ility Is the defined process accepta"le to and usa"le "y the engineersresponsi"le for producing the software product

2elia"ility Is the process designed in such a way that process errors are avoidedor trapped "efore they result in product errors

2o"ustness Can the process continue in spite of unexpected pro"lems

Maintaina"ility Can the process evolve to reflect changing organi#ational requirementsor identified process improvements

2apidity 3ow fast can the process of delivering a system from a givenspecification "e completed



12/50

Process improvement stages

Process measurement

$ttri"utes of the current process are measured. These are a

"aseline for assessing improvements.

Process analysis

The current process is assessed and "ottlenecks and

weaknesses are identified.

Process change

Changes to the process that have "een identified during the

analysis are introduced.



13/50

The process improvement cycle



14/50

Process measurement

4herever possi"le, quantitative process data

should "e collected

3owever, where organi#ations do not have clearly defined

process standards this is very difficult as you don(t know what to

measure. $ process may have to "e defined "efore anymeasurement makes sense.

Process measurements should "e used to

assess process improvements

5ut this does not mean that measurements should drive theimprovements. The improvement driver should "e the

organi#ational o"!ectives.



15/50

Typical#$%ample Process metrics

Time taken for process activities to "e

completed

Calendar time or effort to complete an activity or process.

2esources required for processes or activities

Total effort in person&days.

6um"er of occurrences of a particular event

6um"er of defects discovered during process activities.



16/50

&oal'uestion'(etric Paradigm

7oals 4hat is the organi#ation trying to achieve The o"!ective of

process improvement is to satisfy these goals.

8uestions

8uestions a"out areas of uncertainty related to the goals. )ouneed process knowledge to derive these.

Metrics Measurements to "e collected to answer the questions.



17/50

&( questions

The 78M paradigm is used in process improvement to

help answer three critical questions9

4hy are we introducing process improvement

4hat information do we need to help identify and assess

improvements 4hat process and product measurements are required to

provide this information



18/50

The &( paradigm



19/50

Process analysis

The study of existing processes to understand the

relationships "etween parts of the process and to

compare them with other processes.

Process analysis and process measurement are

intertwined.

)ou need to carry out some analysis to know what to

measure, and, when making measurements, you

inevita"ly develop a deeper understanding of the

process "eing measured.



20/50

Process analysis o!)ectives

To understand the activities involved in the process and

the relationships "etween these activities.

To understand the relationships "etween the process

activities and the measurements that have "een made. To relate the specific process or processes that you are

analy#ing to compara"le processes elsewhere in the

organi#ation, or to ideali#ed or "est practice processes

of the same type.



21/50

Process analysis techniques

Pu"lished process models and process

standards

It is always "est to start process analysis with an existing model.

People then may extend and change this.

8uestionnaires and interviews Must "e carefully designed. Participants may tell you what they

think you want to hear.

*thnographic analysis

Involves assimilating process knowledge "y o"servation. 5estfor in&depth analysis of process fragments rather than for whole&

process understanding.



22/50

Aspects of process analysis

Processaspect

uestions

$doption andstandardi#ation

Is the process documented and standardi#ed across theorgani#ation If not, does this mean that any measurementsmade are specific only to a single process instance If processesare not standardi#ed, then changes to one process may not "e

transfera"le to compara"le processes elsewhere in the company./oftwareengineeringpractice

$re there known, good software engineering practices that are notincluded in the process 4hy are they not included 1oes thelack of these practices affect product characteristics, such as thenum"er of defects in a delivered software system

:rgani#ational

constraints

4hat are the organi#ational constraints that affect the process

design and the ways that the process is performed %or example,if the process involves dealing with classified material, there may"e activities in the process to check that classified information isnot included in any material due to "e released to externalorgani#ations. :rgani#ational constraints may mean that possi"leprocess changes cannot "e made.



23/50

Aspects of process analysis

Process aspect uestions

Communications 3ow are communications managed in the process 3ow docommunication issues relate to the process measurements that have"een made Communication pro"lems are a ma!or issue in manyprocesses and communication "ottlenecks are often the reasons for

pro!ect delays.Introspection Is the process reflective +i.e., do the actors involved in the process

explicitly think a"out and discuss the process and how it might "eimproved $re there mechanisms through which process actors canpropose process improvements

;earning 3ow do people !oining a development team learn a"out the softwareprocesses used 1oes the company have process manuals and

process training programs

Tool support 4hat aspects of the process are and aren(t supported "y softwaretools %or unsupported areas, are there tools that could "e deployedcost&effectively to provide support %or supported areas, are the toolseffective and efficient $re "etter tools availa"le



24/50

Process models

Process models are a good way of focusing attention on

the activities in a process and the information transfer

"etween these activities.

Process models do not have to "e formal or complete

Documents

Ch26 - Process Improvement