Software Quality Assurance Black Box

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Software Quality AssuranceBlack Box

• Guest Daniel GROZA / Seminar Oana FEIDI
• Continental Automotive

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Preview
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Preview

• the problem
• very large or infinite number of test scenarios
• finite amount of time
• impossible to test everything
• the solution
• Software test techniques exist to reduce the
  number of tests to be run whilst still providing
  sufficient coverage of the system under test

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Overview

• Black-box testing
• Test cases derived from specifications
• The focus is not the design, nor the
  implementation
• positive testing
• ? testing the implementation against specified
  conditions
• negative testing
• ? testing the implementation against unspecified
  conditions (unspecified inputs)
• ? stability and robustness of specifications

Input
Output
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Equivalence partition

• create partitions of the input and output values
  of the component
• each partition shall contain a set or range of
  values, chosen such that all values can
  reasonably expected to be treated by the
  component in the same way
• both valid and invalid values are partitioned in
  this way
• For each test case specify
• Input to the component
• Partition exercised
• The expected outcome of the test case
• Test completeness criteria test at least one
  input/output pair for each equivalence partition

Indicates when to stop testing
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Equivalence partition

• Example
• f(int month) want to test this function
• , -1, 0, 1, 2, 3, ., 9, 10, 11, 12, 13, 14, .
• ____________________________________
• invalid1
  valid partition invalid2
• f(int month, int nrdays) want to test this
  function
• 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
• ? ? ? ? ? ? ? ? ? ? ? ?
• 31 28/29 31 30 31 30 31 31 30
  31 30 31
• Valid partition (1, 3, 5, 7, 8, 10, 12 31),
  (4, 6, 9, 11 30),
• Invalid partition (1, 2, 3, 5, 7, 8, 10, 12
  30),

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Boundary Analysis

• refinement of equivalence partitioning for which
  each edge of an equivalence class is a
  representative element of the class
• invalid-input elements are found just beyond the
  ends
• For each test case specify
• the input(s) to the component
• the partition boundaries exercised
• The expected outcome of the test case
• Test completeness criteria test at least one
  input/output pair for each equivalence partition
  and the borders between the equivalence
  partitions

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Boundary Analysis

• Example
• f(int month) want to test this function
• if (month gt 0 month lt 13)
• or
• if (month gt 0 month lt 13)
• , -1, 0, 1, 2, 3, ., 9, 10, 11, 12 , 13, 14,
  .
• _________________________
• valid partition
• Test 0, 1, 12, 13

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Exercise

• Exercise No A1

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State Transition Testing

• use a model of the states the component may
  occupy, transitions between those states, the
  events which cause those transitions, and the
  actions which may result from those transitions
• the model shall comprise states, transitions,
  events, actions and their relationships
• For each test case specify
• the starting state of the component
• the input(s) to the component
• the expected outputs from the component
• the expected final state
• Test completeness criteria 100 of the state
  transition diagram

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State Transition Testing
being born
start
single
getting married
death
reborn
remarried
getting divorced
married
divorced
death
death
remarried
dying
husband dies
widow
death
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Exercise

• List all the possible transitions