Software reliability is dynamic & stochastic. Unlike hardware, software does not age, wear out or rust, unreliability of software is mainly due to bugs or design faults in the software. The exact value of product reliability is never precisely known at any point in its lifetime. The study of software reliability can be categorized into three parts: Modeling, Measurement & improvement. Many Models exist, but no single model can capture a necessary amount of software characteristics. Software reliability improvement is necessary & hard to achieve. It can be improved by sufficient understanding of software reliability, characteristics of software & sound software design. Software Reliability is the most important and most measurable aspect …show more content…
Article Analysis: Reliability: Software Reliability is defined as the probability of the failure free software operation for a specified period of time in a specified environment. Reliability is a probabilistic measure that assumes that the occurrence of failure of software is a random phenomenon. Reliability Process: The reliability process in generic terms is a model of the reliability-oriented aspects of software development, operations and maintenance. The set of life cycle activities and artifacts, together with their attributes and interrelationships that are related to reliability comprise the reliability process. The artifacts of the software life cycle include documents, reports, manuals, plans, code configuration data and test data. Software reliability is dynamic and stochastic. Software reliability curve: Software does not rust, age, wear-out, or deform. Unlike mechanical parts, software will stay as is unless there are problems in design or in hardware. Over time, hardware exhibits the failure characteristics as shown in Figure 1. Known as bathtub curve. Software is not susceptible to the environmental maladies that cause hardware to wear out; therefore, the failure rate curve for software should take the form of the “idealized curve” as shown in the figure below. Undiscovered defects will cause high failure
Reliability refers to system live time, that is, system is running efficiently most of the time. Availability is the probability that the system is continuously available (usable or accessible) during a time interval.
The reliability of a system can be improved through the introduction of redundancy in the system. Some of the examples of redundancy in the operation are as below:
Deliberations on susceptibilities connected to obsolete Operating systems should also be conducted. The system should adopt sophisticated technology that is reliable and proficient.
Information will only have value if customers can access it at the right times. Availability can be affected by system errors, and malicious attacks as well as infrastructure problems. Availability is ensured by maintaining hardware as well as repairing hardware immediately when need arise. A correct functioning operating system should also be maintained in the environment free of software conflicts. Adequate communication bandwidth should also be addressed as well as preventing bottlenecks from occurrence.
Assessment decisions must be made by an assessor who is competent in the field (discipline) that the work is related to. The decision formed by this assessment will be based upon the judgement
IEEE Std 982.1-2005 (Revision of IEEE Std 982.1-1988) - IEEE Standard Dictionary of Measures of the Software Aspects of Dependability
Reliability is described as the degree to which a survey, test, instrument, observation, or measurement course of action generating
Step-1 – intent: A need was realized. In early 1995, the Swedish groups (Sahlqvist and the Marta) were investigating the acquisition of new computer software to run their parts operations. The main reasons where heavy instability of their existing systems. Frequent system failures came from large amounts of modifications of their source code. As a result, they not always rely on the data thorough there present system.
IBMTR. The failure time T, defined as the time to failure since the initial diagnosis,
The Probabilistic approach is based primarily on risk (Event and Fault Tree Analysis), where a number of scenarios are considered and their likeliness is
Now a day’s Information Technology plays an important role in every field whether it is in big Multinational companies, or in Hospital or in school, colleges, bank etc. It is having a wide range. Every field is now a system oriented where each and every person should have knowledge of basic computer. Information technologies also important to beat the competition in various industries. In our survey report we are going to survey and test the reliability of hardware, networks and software in information technology field. Information technology is a combination of Hardware, software and Networks. It is an combining of technology, users and
In the same way (Kanmani et al. 2007 ) introduced the use of neural networks (NN) as a tool for predicting the software errors .( Yang et al. 2007) also proposed a software quality prediction model based on a fuzzy NN identify design errors in software products in the early stages of a software lifecycle. Besides, NN have been utilized to predict early a specific quality attributes.
Though many people interchange system engineering models and software engineering life cycle models, they are defined as two different approaches to software development. System engineering is the technical and technical management process that results in delivered products and systems that exhibit the best balance of cost and performance. As the program progresses from one phase to the next one, so does the system engineering process. It deals with the overall management of engineering project during their life cycle. Its main focus is knowing what the clients and end users wants and needs are satisfied and developing just that all the way through the system’s entire life cycle. Whereas, on the other hand, software engineering focuses on the quality of the product or system, how cost effective it is, is it done within the time-constraints given, whether it is easy to maintain and enhance, and does it work as the requirements defined. Its main focus is on delivering a product that meets the requirement specifications. There are so many models to choose from, as it all depends on what the project needs and entails. Depending on the requirements, allows for the choice of what mode to use.
As the number of universities IS users constantly grows, the issues of software quality seem to be quite relevant in such situation. The elaborated software must provide the reliable work of its users seven days a week and must be as efficient and comfortable as possible. The importance of questions related to software quality is proved by Software Engineering Body of Knowledge (SWEBOK), which is the guideline for all specialist in this domain [7]. One of its areas directly discusses software quality fundamentals, processes and requirements.
In chapter two and chapter five, several helpful mathematical equations in reliability and maintainability management have been mentioned briefly and in attractive way. The reason to address these equations is to clarify the different relations and functions that are used commonly in reliability and maintainability world. In these chapters, some figures and charts have been used to simplify mathematics in reliability and maintainability management field.