Testcover.com - Tutorial - Start Command Example with 3 States

	Testcover.com
		Tutorial - Start Command Example - Finite State Machine with 3 States

Home
Existing User Login
Brochure
Sign up for Risk-Free Trial
About Testcover.com
Frequently Asked Questions
Tutorial with Examples
->Finite State Machine
--->Start Command: 3 States
--->Start Command: 2 States
Performance
WSDL Interface
Background
Partners
Registrations
Contact Information

The Start Command Example illustrates pairwise testing using a finite state machine. Each partition corresponds to a transition between two states. The start command test model has three states, and each state may transition to any of the three states. Thus, there are 3 • 3 = 9 state transitions to test. Test cases for these nine transitions are generated in this example.

For comparison, the start command also is modeled with two states, one of which is a composite state of a hierarchical state machine similar to those of UML. In the second test model there are 2 • 2 = 4 transitions, i.e. 4 partitions. In both models the same blocks are used, and the same pairs are covered. Tradeoffs between the two models are noted.

Requirements summary. The start command may be used alternately on either of two networked hosts to invoke an application. It provides simple prompts to the operator, to offer supported choices and to avoid errors. A production application may run on either of the hosts, but only one at a time. When a host is not runnning the production application, it may be running a comparable test application, or it may be idle.

When the start command runs on this host, it checks the state of this host and the state of the other host. If the state of this host is test or production, the operator is asked if the current database should be dumped. If yes, the database is dumped for future use before the transition to the target state.

Next, if the state of the other host is not production, the operator is asked if the production application should be started on this host. If yes, the operator is asked if this host's production database should be used, or if the database should be restored

• from the other production database dump, or

• from this production database dump.

The production application is started, and the start command exits.

If the state of the other host is production, or if the operator responded no to the start production prompt, then the operator is asked if the test application should be started on this host. If yes, the operator is asked if this host's test database should be used, or if the database should be restored

• from the other production database dump,

• from this production database dump, or

• from the other test database dump.

The test application is started, and the start command exits.

If the operator responded no to the start test prompt, then this host's state becomes idle, and the start command exits.

Test model. In the example, the purpose is to test the normal operation of the start command on this host. That is, to answer the question, "Does the start command produce the correct transitions among the idle, test and production states?" It is possible to model and test the start command itself, its states between prompts and responses, the entry/exit actions it implements, etc. But this example is concerned with system operation based on previously tested subsystems. Thus the details of the start command are beyond the present scope.

In this normal operation test, the state of the other host is assumed not to change during the start command execution.

There are six test factors with values as follows.

Test Factor	Number of Values	Test Factor Values
1. Other state	3	idle test production
2. This state	3	idle test production
3. Dump this db?	2	no yes
4. Start production?	2	no yes
5. Start test?	2	no yes
6. Restore db?	4	no from_other_prod from_this_prod from_other_test

For test factors 3, 4, 5 and 6, the value no stands for no or not prompted.

The request is composed of nine partitions corresponding to the nine state transitions illustrated below.

The request for this test model is shown below. Partition prefixes (e.g. 3-II, 3-IT, etc.) are used to distinguish the test cases of different partitions.
Start Command with 3 states Other state This state Dump this db? Start production? Start test? Restore db? #3-II idle to idle idle test production idle no no no no #3-IT idle to test idle test production idle no no yes no from_other_prod from_this_prod from_other_test #3-IP idle to production idle test idle no yes no no from_other_prod from_this_prod #3-TI test to idle idle test production test no yes no no no #3-PI production to idle idle test production no yes no no no #3-TT test to test idle test production test no yes no yes no from_other_prod from_this_prod from_other_test #3-TP test to production idle test test no yes yes no no from_other_prod from_this_prod #3-PT production to test idle test production no yes no yes no from_other_prod from_this_prod from_other_test #3-PP production to production idle test production no yes yes no no from_other_prod from_this_prod

The nine results tables follow.

#1. idle to idle

Test
Case ID Other state This state Dump this db? Start production? Start test? Restore db? Combo
Countdown

3 Values 1 Value 1 Value 1 Value 1 Value 1 Value 25

3-II1 idle idle no no no no 10

3-II2 test idle no no no no 5

3-II3 production idle no no no no 0

#2. idle to test

Test
Case ID Other state This state Dump this db? Start production? Start test? Restore db? Combo
Countdown

3 Values 1 Value 1 Value 1 Value 1 Value 4 Values 46

3-IT1 test idle no no yes from_other_test 31

3-IT2 production idle no no yes no 22

3-IT3 idle idle no no yes from_other_prod 13

3-IT4 test idle no no yes from_this_prod 8

3-IT5 idle idle no no yes no 7

3-IT6 production idle no no yes from_other_prod 6

3-IT7 production idle no no yes from_this_prod 5

3-IT8 idle idle no no yes from_other_test 4

3-IT9 test idle no no yes from_other_prod 3

3-IT10 test idle no no yes no 2

3-IT11 production idle no no yes from_other_test 1

3-IT12 idle idle no no yes from_this_prod 0

#3. idle to production

Test
Case ID Other state This state Dump this db? Start production? Start test? Restore db? Combo
Countdown

2 Values 1 Value 1 Value 1 Value 1 Value 3 Values 32

3-IP1 idle idle no yes no no 17

3-IP2 test idle no yes no from_other_prod 8

3-IP3 idle idle no yes no from_this_prod 3

3-IP4 idle idle no yes no from_other_prod 2

3-IP5 test idle no yes no no 1

3-IP6 test idle no yes no from_this_prod 0

#4. test to idle

Test
Case ID Other state This state Dump this db? Start production? Start test? Restore db? Combo
Countdown

3 Values 1 Value 2 Values 1 Value 1 Value 1 Value 32

3-TI1 idle test no no no no 17

3-TI2 test test yes no no no 8

3-TI3 production test no no no no 3

3-TI4 test test no no no no 2

3-TI5 idle test yes no no no 1

3-TI6 production test yes no no no 0

#5. production to idle

Test
Case ID Other state This state Dump this db? Start production? Start test? Restore db? Combo
Countdown

2 Values 1 Value 2 Values 1 Value 1 Value 1 Value 26

3-PI1 idle production no no no no 11

3-PI2 test production yes no no no 2

3-PI3 test production no no no no 1

3-PI4 idle production yes no no no 0

#6. test to test

Test
Case ID Other state This state Dump this db? Start production? Start test? Restore db? Combo
Countdown

3 Values 1 Value 2 Values 1 Value 1 Value 4 Values 56

3-TT1 test test yes no yes from_other_test 41

3-TT2 idle test no no yes from_other_prod 29

3-TT3 production test yes no yes no 20

3-TT4 test test no no yes from_this_prod 14

3-TT5 production test no no yes from_other_test 11

3-TT6 idle test yes no yes from_this_prod 8

3-TT7 idle test no no yes no 6

3-TT8 production test yes no yes from_other_prod 4

3-TT9 production test yes no yes from_this_prod 3

3-TT10 idle test no no yes from_other_test 2

3-TT11 test test no no yes from_other_prod 1

3-TT12 test test yes no yes no 0

#7. test to production

Test
Case ID Other state This state Dump this db? Start production? Start test? Restore db? Combo
Countdown

2 Values 1 Value 2 Values 1 Value 1 Value 3 Values 40

3-TP1 idle test no yes no no 25

3-TP2 test test no yes no from_other_prod 16

3-TP3 idle test yes yes no from_this_prod 7

3-TP4 test test yes yes no no 4

3-TP5 idle test yes yes no from_other_prod 2

3-TP6 test test no yes no from_this_prod 0

#8. production to test

Test
Case ID Other state This state Dump this db? Start production? Start test? Restore db? Combo
Countdown

2 Values 1 Value 2 Values 1 Value 1 Value 4 Values 47

3-PT1 idle production no no yes no 32

3-PT2 test production yes no yes from_other_test 20

3-PT3 test production no no yes from_other_prod 14

3-PT4 idle production yes no yes from_this_prod 8

3-PT5 idle production yes no yes from_other_prod 6

3-PT6 test production yes no yes no 4

3-PT7 test production no no yes from_this_prod 2

3-PT8 idle production no no yes from_other_test 0

#9. production to production

Test
Case ID Other state This state Dump this db? Start production? Start test? Restore db? Combo
Countdown

2 Values 1 Value 2 Values 1 Value 1 Value 3 Values 40

3-PP1 idle production no yes no no 25

3-PP2 test production no yes no from_other_prod 16

3-PP3 idle production yes yes no from_this_prod 7

3-PP4 test production yes yes no no 4

3-PP5 idle production yes yes no from_other_prod 2

3-PP6 test production no yes no from_this_prod 0

In each of the nine partitions, all pairs of factor values are covered. Moreover, the number of test cases is the minimum possible in each of the partitions. The total number of test cases for this model is 63 (compared with 35 for the 2-state model).

The final illustration for the 3-state model shows how the test cases can be ordered to create a path through the test model states. In a successful test run, each transition would set up the initial conditions for the following test case. In this example, the test cases are sorted by the 3 other state values to create 3 corresponding test runs. In each run the transitions for this host are ordered so that the resulting state of each test case sets up the initial state of the next.

Run 1. Other state idle

Test
Case ID Other state This state Dump this db? Start production? Start test? Restore db?

3-II1 idle idle no no no no

3-IT3 idle idle no no yes from_other_prod

3-TI1 idle test no no no no

3-IT5 idle idle no no yes no

3-TI5 idle test yes no no no

3-IT8 idle idle no no yes from_other_test

3-TT2 idle test no no yes from_other_prod

3-TT6 idle test yes no yes from_this_prod

3-TT7 idle test no no yes no

3-TT10 idle test no no yes from_other_test

3-TP1 idle test no yes no no

3-PI1 idle production no no no no

3-IT12 idle idle no no yes from_this_prod

3-TP3 idle test yes yes no from_this_prod

3-PI4 idle production yes no no no

3-IP1 idle idle no yes no no

3-PT1 idle production no no yes no

3-TP5 idle test yes yes no from_other_prod

3-PT4 idle production yes no yes from_this_prod

3-TI1 idle test no no no no

3-IP3 idle idle no yes no from_this_prod

3-PT5 idle production yes no yes from_other_prod

3-TI1 idle test no no no no

3-IP4 idle idle no yes no from_other_prod

3-PP1 idle production no yes no no

3-PP3 idle production yes yes no from_this_prod

3-PP5 idle production yes yes no from_other_prod

3-PT8 idle production no no yes from_other_test

In this run test case 3-TI1 was repeated twice to set up its following test cases.

Run 2. Other state test

Test
Case ID Other state This state Dump this db? Start production? Start test? Restore db?

3-II2 test idle no no no no

3-IT1 test idle no no yes from_other_test

3-TI2 test test yes no no no

3-IT4 test idle no no yes from_this_prod

3-TI4 test test no no no no

3-IT9 test idle no no yes from_other_prod

3-TT1 test test yes no yes from_other_test

3-TT4 test test no no yes from_this_prod

3-TT11 test test no no yes from_other_prod

3-TT12 test test yes no yes no

3-TP2 test test no yes no from_other_prod

3-PI2 test production yes no no no

3-IT10 test idle no no yes no

3-TP4 test test yes yes no no

3-PI3 test production no no no no

3-IP5 test idle no yes no no

3-PP2 test production no yes no from_other_prod

3-PP4 test production yes yes no no

3-PP6 test production no yes no from_this_prod

3-PT2 test production yes no yes from_other_test

3-TP6 test test no yes no from_this_prod

3-PT3 test production no no yes from_other_prod

3-TI2 test test yes no no no

3-IP2 test idle no yes no from_other_prod

3-PT6 test production yes no yes no

3-TI2 test test yes no no no

3-IP6 test idle no yes no from_this_prod

3-PT7 test production no no yes from_this_prod

In this run test case 3-TI2 was repeated twice to set up its following test cases.

Run 3. Other state production

Test
Case ID Other state This state Dump this db? Start production? Start test? Restore db?

3-II3 production idle no no no no

3-IT2 production idle no no yes no

3-TI3 production test no no no no

3-IT6 production idle no no yes from_other_prod

3-TI6 production test yes no no no

3-IT7 production idle no no yes from_this_prod

3-TT3 production test yes no yes no

3-TT5 production test no no yes from_other_test

3-TT8 production test yes no yes from_other_prod

3-TT9 production test yes no yes from_this_prod

3-TI3 production test no no no no

3-IT11 production idle no no yes from_other_test

In this run test case 3-TI3 was repeated once to set up its following test case.

For comparison, the start command also is modeled with two states. Reducing the number of partitions from 9 to 4 reduces the number of test cases by 44% in this example.