Standards ensure that an interface will enable to a connection of two components.
There are many benefits to having standards for interfacing.Interchangeabilityinteroperabilityportabilityreduces cost and riskincreased life cycle
There are different standards of formality:Formal Standards, De Jure Standards De Facto Standards.
IDEF0 is a legal standard for system development.
Common Request Broker Architecture (CORBA) is basically a standard used for software development.
This standard permit programmers to integrate software modules resident on the same network by treating each application as an object.This was developed in association with industries like HP, Hyperdesk, SUN and so on.CORBA is a formal standards and it is a de jure standard in the US.CORBA is the interface definition language or a IDL, it is a formal standard adopted by ISO.CORBA is a de facto standard in other parts of the world.
Integration is the process of assembling the system from its components which must be assembled from its CIs.Qualification is ensuring that the system actually meets the customer requirements.
The Exit Criterion for Integration and Qualification is acceptance of the design by the stakeholders.
Verification , Validation and Acceptance are the three procedures in the qualification process.Verification is the determination that the system will do us right.Validation determines that the right system was built.Acceptability is the process by which the customer or the stakeholder accept the system that was designed.
The purpose of qualification is not only to find faults and failures, but also to prevent them and to providecomprehensive diagnosis about their location and cause.
The three laws of software testing are:Pesticide Paradox- Every method use to prevent a bug(fault) leaves a residue of subtler bugs(faults)
Complexity Barrier- The complexity of bugs(faults) grows to the limits of our ability to manage that complexity
Code Migrates to Data - Hardware and people migrate to software which eventually migrate to data.
Fault Categorization and their consequences:Mild Fault is something which can be discardedModerate Faults may be a problem, however you do not need to invest too much on this kind of moderate errorsAnnoying Faults annoys usersDisturbing Faults these will refuse legitimate transactionsSerious Faults this loses track of input and output.Very Serious Faults there can be mixing up of inputs and outputs.Extreme Faults this is when very serious faults are happening frequentlyIntolerable Faults causes long term unrecoverable data corruption.
There are four levels of qlaification palnning:Plan the qualification processPlan the qualification approachesPlan the qualification activitiesPlan specific tests
There are four caregories of qualification methods:InspectionAnalysis and SimulationInstrumented TestingDemonstration
There are different types of tests to be carried out on a system because the system has to be able to perform under various situations. These testing methods are:
Funtional Test- Examine input and ouput under mostly nominal conditionsStructural Test- Examines structure of the system and its proper functioningPerformance Tests- Paticular attention to extreme environments in structural tests.Recovery Tests- Failure modes created- system's ability to return to operating mode tested.Interface Tests- Examine all interface conditionsStress Testing- Above normal loads are placed to see system's performance and get systems breaking point