ISTQB CT-MBT case studies
ISTQB CT-MBT · Put your knowledge to work in context.
The ISTQB® Certified Tester Model-Based Tester (CT-MBT) is a Specialist-level certification in the ISTQB® portfolio. ISTQB® describes it as focusing "on an advanced test approach of using models for testing" and as extending and supporting classic test design techniques - equivalence partitioning, boundary value analysis, decision table testing, state transition testing and use case testing - calling it "an innovative approach to improve effectivity and efficiency of the test process." That framing tells you who it is for: testers and test analysts who already design tests with those classic techniques and now want to derive tests systematically from models instead of writing every case by hand. The ISTQB CT-MBT case studies are 5 cases and about 4,005 words.
1Pilot decision: turning an architecture state machine into a generatable test model
Your team maintains the control software for an automated warehouse shuttle. Three testers own a regression suite of 1,420 manual test cases; a full run takes nine working days, and releases ship every four weeks.
799 words, about 4 min2Choosing notations for a claims system with a lifecycle and a rule set
An insurer is replacing its claims adjudication system, and two very different behaviours sit inside the same release. First, a claim lifecycle: received, validated, medical review, pending-information, approved, rejected, paid, appealed, closed - with re-entry from appeal back to review and from pending-information back to validated.
855 words, about 4 min3100% state and transition coverage, three field escapes
Your team tests the firmware of a connected thermostat. Its behaviour is specified as a state machine with 9 states and 24 transitions, including guards on measured temperature and occupancy, three timers (minimum compressor off-time, boost duration, away-delay), and a frost-protection interrupt that can fire in any state.
761 words, about 4 min4Fitting 400 executions into a 4,860-case generated suite
Your team is testing a payment terminal's configuration layer. Five parameters drive behaviour: card scheme (4 values), transaction type (3), currency exponent (2), terminal capability profile (5) and connectivity mode (3).
762 words, about 4 min5MBT in CI: model drift, a departing expert and an audit gap
A medical-device company has run model-based testing for a year on patient-monitor firmware. The model - a state machine plus a data model of 40 settings - lives in the modelling tool's proprietary repository.
828 words, about 4 min