Writing Requirements

Characteristics of Requirement Statements

  • Necessary
  • Appropriate
  • Umambiguous
  • Complete
  • Singular
    • Cannot be combination
  • Feasible
  • Verifiable
  • Correct
  • Conforming
    Standards of organisation

Characteristics of Requirement Set

  • Complete
  • Consistent
  • Feasible
  • Comperehensible
  • Able to be validated
INCOSE
40 rules for writing good textual requirements

Guidelines for Writing Requirements

Writing well-formed requirements can be achieved by using the following guidelines:

  • Use a style guide (R41, R43, R44).
  • Use a standard template for a single sentence (R3, R19).
  • Use a glossary to define terms (R4, R39, R40).
  • Use correct English expression (R13, R14, R15).
  • Use a subject appropriate to the level (R33).
  • Use explicit lists (R24, R29, R30).
  • Use the active rather than the passive voice (R2).
  • Use the definite article (R1).
  • Use the same term to mean the same thing (R38)
  • Avoid vague words (R7, R34).
  • Avoid superfluous words (R11, R22, R23).
  • Avoid unbounded statements (R10, R27).
  • Avoid escape clauses (R9).
  • Avoid the use of conjunctions (R18, R20).
  • Use of logical conjunctions (R18, R20).
  • Avoid unecessary precision (R28).
  • Be precise when necessary
  • Use units, ranges and