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ECE 322

SOFTWARE TESTING AND MAINTENANCE

Assignment #2

(return to the appropriate box- 2nd floor of DICE building)

Total: 40 points

Value 10 points

1. Develop software specifications for a simple e-shopping system using the formalism of

finite state machines. Consider some selected functionality. Make appropriate

assumptions.

Note: there could be a variety of possible solutions; there is nothing wrong about that.

Your answer will be evaluated on a basis of its completeness and correctness (taking into

consideration the assumptions you have made).

Value 10 points

2.Suggest a collection of test cases to test a procedure finding a maximum of three integer

numbers

maxofThreeNumbers(int n1, int n2, int n3)

Consider (i) exhaustive testing and (ii) error guessing.

3.(i) Suppose that an application has n inputs (variables) and each variable partitions its

input space in m equivalence classes. Determine the number of equivalence classes. How

many tests do you require. Could be the number of tests made lower? Do detailed

calculations for n =10 and m =10.

(ii) a system invokes function S if the reading of a given sensor is within the [a, b] or [c,

d], b <c. The entire range of possible values is [-50, 50]. Identify equivalence classes.

List a collection of tests.

(iii) generalize the problem in (ii) by considering that there are two sensors where the

function is invoked for the sensors’ readings are in [ai, bi] or [ci, di], bi <ci, i=1, 2. How

many test cases do you require here.

Value 10 points

4. Consider a 3-dimensional input domain described as

W = [0, 10] [-5, 20] [0, 7]

(viz. there are 3 input variables assuming values in the corresponding intervals). In this

domain there are three equivalence classes

W1= {(x, y, z) | max (|x-1|, |y-1|, |z-1|) e}

× ×

≤

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W2= {(x, y, z) | max (|x-5|, |y-10|, |z-4|) e}

W3 = W-W1-W2

where e is a certain positive number. What should be possible values of e so that these

equivalence classes form a partition?

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