Overview
ISO/IEC 11411:1995 defines a minimal, standardized notation for representing software state transitions to improve human communication during requirements analysis and design. The standard specifies diagrammatic and tabular ways to show states, transitions, conditions and actions so teams can clearly describe how software moves between states. It is intended for use across interactive software, data communication software, and language/command processing.
Key Topics
- States and identifiers
- Definitions of initial, final, initial/final, and intermediate states.
- Each state has a unique state name and may have a numeric state No. for tabular representation.
- Transitions
- Formal structure of a transition: direction part (previous and next state identifiers), condition part, and action part.
- Distinguishes transitions to another state and self-transitions (same state).
- Rules requiring each transition to have a previous and next state; condition patterns for mutually exclusive transitions.
- State diagrams
- Graphical notation: states shown as symbols (circle, rectangle, etc.), transitions as arrows with adjacent condition / action text, and connectors with unique identifiers for broken arcs.
- Flexibility in symbol shapes and arrow styles; both hand-drawn and machine-drawn charts are acceptable.
- State tables
- Tabular alternative: states listed with intersections showing transitions; intersections contain next state and optional action.
- Option to use state names instead of state numbers and omission of action part when not applicable.
- Usage and restrictions
- One and only one initial state; zero or more final states; one or more transitions required.
- Drawing conventions and layout are flexible; the standard does not mandate specific forms or templates.
Applications and Users
ISO/IEC 11411 is practical for:
- Software architects and designers documenting system behavior and state machines
- Requirements analysts and technical writers producing clear state diagrams and state tables
- Test engineers deriving test cases from state transitions and conditions
- Protocol designers and developers of interactive or data communication systems
- Teams needing consistent visual language to communicate behavioral requirements across stakeholders
Benefits include clearer requirement reviews, reduced ambiguity in state-dependent behavior, and a lightweight, general-purpose notation usable outside telecommunications-specific tools.
Related Standards
- CCITT Rec. Z.100 / Z.120 - Specification and Description Language (SDL) (includes graphical SDL-GR used in telecom)
- ISO 9074:1989 - ESTELLE, a formal description technique based on extended state transition models
Keywords: ISO/IEC 11411, state transition, state diagram, state table, software requirements, software design, interactive software, data communication, notation, symbols, transitions.
Open preview (PDF)Information technology — Representation for human communication of state transition of software
