State budget educational institution
higher education in the Moscow region
"University of Dubna"
Branch "Kotelniki"
Department of Information Technology in Management
department name
abstract
By discipline Design, architecture and construction of software tools
Topic "Common features of defects, errors and risks in complex software"
Is done by a student
______41______groups
______4_______ courses
Kuznetsov V.O.
Full name
Checked:
Position: Ph.D., Associate Professor of the Department
Name: Podlevsky A.P.
Grade ______________
Date November 2, 2021
Signature ________________
Kotelniki -2021
CONTENT
INTRODUCTION 3
CHAPTER 1. COMMON FEATURES OF DEFECTS, ERRORS AND RISKS IN
COMPLEX SOFTWARE 4
1.1 The concept of a program error 5
1.2 Error levels, types and sources 8
CHAPTER 2. CAUSES AND PROPERTIES OF DEFECTS, ERRORS AND
MODIFICATIONS IN COMPLEX SOFTWARE 11
2.1 Causes of risks 12
CHAPTER 3. RISKS IN THE FORMATION OF REQUIREMENTS FOR THE
CHARACTERISTICS OF COMPLEX SOFTWARE 14
CONCLUSION 17
REFERENCES 18
2
INTRODUCTION
Statistics of errors and defects in software packages and their characteristics in
specific types of software projects can serve as guidelines for developers in the
allocation of resources in the software life cycle and protect them from excessive
optimism when assessing the achieved quality of software products. Sources of
errors in the PS are specialists - specific people with their individual
characteristics, qualifications, talent and experience. At the same time, it is
possible to single out predictable modifications, extensions and improvements of
the software system and changes due to the identification of random, unpredictable
defects and errors.
As a result, the flow density and the size of the necessary adjustments in the
modules and components during the development and maintenance of the PS can
vary by a dozen times. However, in large software complexes, the statistics and
distribution of the types of changes performed for teams of different specialists are
leveled and quite general patterns appear that can be used as guidelines for their
identification and systematization. This can be helped by assessments of typical
defects, modifications and adjustments, by accumulating and generalizing them
based on the experience of creating certain classes of software systems in specific
enterprises.
CHAPTER 1. GENERAL FEATURES OF DEFECTS, ERRORS AND RISKS IN
COMPLEX SOFTWARE
The concept of "risks" includes negative events and their magnitudes, reflecting
losses, damages or damage from processes or products caused by defects in the
design of requirements, shortcomings in the justification of PS projects, as well as
in subsequent stages of development, implementation and the entire life cycle of
software packages. In the life cycle of the PS, it is not always possible to achieve
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the required positive effect and some damage may appear - a risk in the created
projects, software products and their characteristics. Risks manifest themselves as
negative consequences of defects in the functioning and use of the software, which
can cause damage to the system, the environment or the user as a result of the
deviation of the characteristics of objects or processes from those specified by the
customer's requirements agreed with the developers.
Assessments of the quality of software tools can be carried out from two positions:
from the position of positive efficiency and direct adequacy of their characteristics
to the purpose, goals of creation and use, as well as from the negative position of
possible damage in this case - the risk from using the software or system. Quality
indicators mainly reflect the positive effect of the application of the system or PS,
and the main task of the project developers is to ensure high quality values. Risks
characterize the possible negative consequences of defects or damage to users in
the application and operation of the software and system, and the task of
developers is to reduce defects and eliminate risks. Therefore, the methods and
systems of quality management in the software life cycle are close to the methods
of analysis and risk management of projects of software complexes, they should
complement them and jointly contribute to the improvement of software products
and systems based on them.
Characteristics of defects and risks are directly related to the achieved correctness,
safety and reliability of the programs and help:
• evaluate the actual state of the project and plan the necessary labor intensity and
duration for its positive completion;
• choose methods and tools for automating testing and debugging programs that are
adequate to the current state of development and maintenance of the software, the
most effective for eliminating certain types of defects and risks;
• calculate the necessary effectiveness of countermeasures and additional means of
operational protection against potential defects and undetected errors;
• evaluate the required computer resources for expanding memory and
performance, taking into account the cost of implementing countermeasures when
modifying and eliminating errors and risks.
1.1 The concept of an error in a program
The concept of an error in a program - in the general case, under an error
subsection
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