Software Testing guide

A cause-effect graph is a directed graph that maps a set of causes to a set of effects. The causes may be thought of as the input to the program, and the effects may be thought of as the output. Usually the graph shows the nodes representing the causes on the left side and the nodes representing the effects on the right side. There may be intermediate nodes in between that combine inputs using logical operators such as AND and OR. Constraints may be added to the causes and effects. These are represented as edges labelled with the constraint symbol using a dashed line. For causes, valid constraint symbols are E (exclusive?), O (one and only one?), and I (at least one?). For effects, valid constraint symbols are R (Require?) and M (Mask?). (This information needs to be verified.) The graph's direction is as follows: (XXX: a figure would represent this better)Causes --> intermediate nodes --> Effects It is a proven technique for effective requirements validation and test case de...

Equivalence partitioning is a systematic process that identifies, on the basis of whatever information is available, a set of interesting classes of input conditions to be tested, where each class is representative of (or covers) a large set of other possible tests. If partitioning is applied to the product under test, the product is going to behave in much the same way for all members of the class. The aim is to minimize the number of test cases required to cover these input conditions. There are two distinct steps. The first is to identify the equivalence classes (ECs) and the second is to identify the test cases. (1) Identifying equivalence classes For each external input: (i) If the input specifies a range of valid values, define one valid EC (within the range) and two invalid Ecs (one outside each end of the range). Example: If the input requires a month in the range of 1-12, define one valid EC for months 1 through 12 and two invalid ECs (month 12). (ii) I...

Testing methodologies are set of rules or guidelines that are followed to minimize the number of test cases and also provide with maximum test coverage. The following methods are commonly used: · equivalence partioning · boundary-value analysis · error guessing The following are lesser-used methods: · cause-effect graphing · syntax testing · state transition testing · graph matrix

ANSI = 'American National Standards Institute', the primary industrial standards body in the U.S.; publishes some software-related standards in conjunction with the IEEE and ASQ (American Society for Quality).

IEEE = 'Institute of Electrical and Electronics Engineers' - among other things, creates standards such as 'IEEE Standard for Software Test Documentation' (IEEE/ANSI Standard 829), 'IEEE Standard of Software Unit Testing (IEEE/ANSI Standard 1008), 'IEEE Standard for Software Quality Assurance Plans' (IEEE/ANSI Standard 730), and others.

ISO = 'International Organisation for Standardization' - The ISO 9001:2000 standard (which replaces the previous standard of 1994) concerns quality systems that are assessed by outside auditors, and it applies to many kinds of production and manufacturing organizations, not just software. It covers documentation, design, development, production, testing, installation, servicing, and other processes. The full set of standards consists of: (a)Q9001-2000 - Quality Management Systems: Requirements; (b)Q9000-2000 - Quality Management Systems: Fundamentals and Vocabulary; (c)Q9004-2000 - Quality Management Systems: Guidelines for Performance Improvements. To be ISO 9001 certified, a third-party auditor assesses an organization, and certification is typically good for about 3 years, after which a complete reassessment is required. Note that ISO certification does not necessarily indicate quality products - it indicates only that documented processes are followed. Also see http://www.i...

CMM = 'Capability Maturity Model', developed by the SEI. It's a model of 5 levels of organizational 'maturity' that determine effectiveness in delivering quality software. It is geared to large organizations such as large U.S. Defense Department contractors. However, many of the QA processes involved are appropriate to any organization, and if reasonably applied can be helpful. Organizations can receive CMM ratings by undergoing assessments by qualified auditors. Level 1 - characterized by chaos, periodic panics, and heroic efforts required by individuals to successfully complete projects. Fw if any processes in place; successes may not be repeatable. Level 2 - software project tracking, requirements management, realistic planning, and configuration management processes are in place; successful practices can be repeated. Level 3 - standard software development and maintenance processes are integrated throughout an organization; a Software Engineering Process Group i...