Measurements Makes Walls White! Acceptance Criterion Fit Criterion Test Criterion Measure of Effectiveness (MoE) Measure of Performance (MoP) Postcondition Minimal Guarantee Success Guarantee Quality of Service (QoS) People in different domains use many different terms for the measurements that they make to verify that products and services meet their requirements. These terms are not exact synonyms but indicate important variations of approach. We won’t try to teach them all here.

Verification Method Any combination of { Test | Inspection | Analysis | Demonstration | Similarity} Can be broken down further, e.g. bench test field test eyeball inspection ultrasound inspection … Verification is not necessarily by test: not everything can be tested, for reasons such as cost, safety, and simple practicality – some things like reliability could take years to demonstrate by test. Note too that the situation is very different for software and for embedded systems which include a range of different kinds of hardware (mechanical, hydraulic, electrical, electronic, …).

Acceptance Criteria* Define the Measure(s) that you insist must be reached for you to accept the product from the supplier/developer Goal Verification Method Acceptance Criteria Bright lamp Lab Test 50 Lumens, for 60 minutes In a Customer / Supplier setting (as opposed, say, to in-house development) there must be a clear definition of what will constitute success at acceptance time. Where Test is the Verification Method, Acceptance (Test) Criteria must state what the tester has to measure to decide if the test is passed. Where a Goal has more than 1 Verification Method, each one must be accompanied by suitable Acceptance Criteria. 2 criteria for 1 function, in this case * this is the plural. Singular: A Criterion

Quality of Service Measure Not enough to measure a Service just once, at Acceptance / Handover Acceptance measures ability to meet requirements correctly, basically once QoS measures service delivery “continuously” e.g. weekly, or for every transaction, etc Goal Quality of Service Measure Comfortable ambience Any dirty or damaged carpet must be replaced with new carpet within 48 hours of being reported. Quality of Service relates to the service as delivered to its (functional) beneficiaries. Their experience of a service is basically continuous, and hard to measure as it has a strong subjective component. Notice that people get an end-to-end view of a service, eg noticing a problem, complaining about it, pushing to get it resolved, seeing it done (we hope). In contrast, a service “provider” sees a narrower scope: receiving a complaint is often the earliest they know about a problem. Their measurements therefore can easily look unrepresentative to service beneficiaries. implies “every time”