Slide 1Slide 2OverviewThe requirements pyramidTraceability requirements pyramid Role of TraceabilitySlide 7Slide 8Use Case DiagramSlide 10Basic flow of the use case place an orderSlide 12ConversationSlide 14All ScenariosSlide 16Finding scenarios in a use caseInfinite loopsStatsSlide 20Slide 21Generating test casesStep 1: Identify variables for each use case stepSlide 24Options that were identified for variables in the basic flowStep 3: Combine options to be tested into test casesSlide 27Combine options to create test casesSlide 29Test PathsStep 4: Assign values to variables(Test Case 1 for test path 1)Traceability activities mapped to RUP phases ConclusionsTraceability from Use Cases to Test CasesGannon University Dr. Frank Xu01/14/20191 CIS310 Software Design & TestingPeter Zielczynski!([email protected]), Director of Technology Solutions, The A Consulting Team, Inc.http://www.ibm.com/developerworks/rational/library/04/r-3217/01/14/20192 CIS310 Software Design & TestingOverviewThe article illustrates a formal method of deriving functional test cases from use cases,including how to create a use case, derive all scenarios, and create reasonable test cases, as well as use IBM® Rational® RequisitePro for traceability from use cases to scenarios and test cases.01/14/20193 CIS310 Software Design & TestingThe requirements pyramid01/14/20194 CIS310 Software Design & TestingTraceability requirements pyramid01/14/20195 CIS310 Software Design & TestingRole of TraceabilityCoverage AnalysisVerify that an implementation fulfills all requirementsEverything that the customer requested was implementedVerify that the application does only what was requestedDon't implement something that the customer never asked forHelp with change management: When some requirements change, we want to know which test cases should be redone to test this change01/14/20196 CIS310 Software Design & Testing01/14/20197 CIS310 Software Design & Testing01/14/20198 CIS310 Software Design & TestingUse Case DiagramThe general format of a use case is:Brief descriptionFlow of eventsBasic flowAlternative flow 1Alternative flow 2Special requirementsPreconditionsPost-conditionsExtension pointsContext diagramActivity diagram01/14/20199 CIS310 Software Design & TestingThe basic flow contains the most popular sequence of actions, the steps that happen when everything goes correctly. Alternative flows represent variations of the flow, including less usual cases and error conditions. A context diagram is a part of a use case diagram showing the relationships of this particular use case to actors and other use cases. An activity diagram is a flow chart that explains the use case. The context diagram and the activity diagram are not necessary, but help you visualize the use case and its position in the project.01/14/201910 CIS310 Software Design & TestingBasic flow of the use case place an orderB1 User enters web site address in the browser.System displays login page.B2 User enters an email address and a password.System confirms correct login, presents main page, and prompts for a search string.B3 User enters search string – partial name of a book.System returns all books matching search criteria.B4 User selects a book. System presents detailed information about a book.B5 User adds the book to a shopping cart.Shopping cart contents is presented to the user.B6 User selects "proceed to checkout" option.System asks for confirmation of a shipping address.B7 User confirms shipping address.System presents shipping options.B8 User selects shipping option.Systems asks which credit card will be used.B9 User confirms credit card that is stored in the system.System asks for final confirmation to place an order.B10 User places the order.System returns a confirmation number.01/14/201911 CIS310 Software Design & TestingAlternative flows that were included in the use case "place an order"Table 1: Alternative flowsA1 Unregistered userA2 Invalid passwordA3 No books matching search criteria were foundA4 Decline a bookA5 Continue shopping after storing a book in the shopping cartA6 Enter a new addressA7 Enter a new credit cardA8 Cancel order01/14/201912 CIS310 Software Design & TestingConversationThe following convention is used for naming the flows:Basic flow: BAlternative flows: A1, A2, A3, ...Steps in a basic flow: B1, B2, B3, ...Steps in alternative flow 1: A1.1, A1.2, A1.3, ...Steps in alternative flow 2: A2.1, A2.2, A2.3, ...01/14/201913 CIS310 Software Design & Testing01/14/201914 CIS310 Software Design & TestingAll Scenarios01/14/201915 CIS310 Software Design & Testing01/14/201916 CIS310 Software Design & TestingFinding scenarios in a use case a hypothetical graph representing a use case with a basic flow B and alternative flows A1, A2, A3, and A4. To find all scenarios, we need to draw all possible lines through this graph.01/14/201917 CIS310 Software Design & TestingInfinite loopsThe reasonable approach is to do the basic flow once, do a loop once, and then do a loop a second time.01/14/201918 CIS310 Software Design & TestingStatsThe book ordering example has a basic flow and eight alternative flows. Four of them are going backwards, and the other four are going forward. If you want to describe all possible use case combinations, you will have over four thousand scenarios there are eight alternative flows, four of which we may want to do twice because they are loops going backwards, so together it is 2 to the power of (8+4), which is equal to 4096. Obviously we don't need to do all of them!01/14/201919 CIS310 Software Design & TestingChoose which ones represent a reasonable subset of these four thousand scenarios. Usually it is wise to select a basic flow, one scenario covering each alternative flow, and some reasonable combinations of alternative flows. Using the examples in Table 1, it probably won't make sense to do a scenario that contains both flows A1 and A7, because they are so far apart on the diagram that they don't have any influence on each other. But it makes sense to do A1 and A2, since they are immediately after each other and may be correlated.01/14/201920 CIS310 Software Design & TestingTable 2: Capturing selected scenariosScenario 1 Basic Flow Scenario 9 A8 Scenario 2 A1 Scenario 10 A1, A2 Scenario 3 A2