# Chapter 19. Orthogonal Arrays Exercise

Let’s apply the orthogonal array test technique to the Omninet project. Suppose you need to test compatibility of various kiosk configurations. According to the Omninet System Requirements Document, we intend to support kiosks running configurations based on three major factors, each set to one of the options shown:

• Operating SystemWindows XP or Linux

• BrowserInternet Explorer (Windows only), Netscape, or Opera

• ConnectionDSL, dial-up, or cable

The next few pages show orthogonal arrays you might use to test this. The exercise consists of four steps.

1. Select the appropriate array from Table 19-1, Table 19-2, and Table 19-3.

Table 19-1. Orthogonal Array 1

Factors

Test

1

2

3

1

0

0

0

2

0

1

1

3

1

0

1

4

1

1

0

Table 19-2. Orthogonal Array 2

Factors

Test

1

2

3

4

1

0

0

0

0

2

0

1

1

2

3

0

2

2

1

4

1

0

1

1

5

1

1

2

0

6

1

2

0

2

7

2

0

2

2

8

2

1

0

1

9

2

2

1

0

Table 19-3. Orthogonal Array 3

Factors

Test

1

2

3

4

5

1

0

0

0

0

0

2

0

1

1

1

1

3

0

2

2

2

2

4

0

3

3

3

3

5

1

0

1

2

3

6

1

1

0

3

2

7

1

2

3

0

1

8

1

3

2

1

0

9

2

0

2

3

1

10

2

1

3

2

0

11

2

2

0

1

3

12

2

3

1

0

2

13

3

0

3

1

2

14

3

1

2

0

3

15

3

2

1

3

0

16

3

3

0

2

1

2. Map the factors (OS, browser, and connection) on to the column headings.

3. Map the options within each factor into the array cells.

4. Handle rows with spare cells and pairs that represent impossible configuration combinations.

Of these, you’ve seen how to handle steps 1 through 3. Step 4 will be clear if you keep in mind the rules about handling rows and tester’s choice (tilde ~) cells. I suggest 30 minutes as a time limit. When you’re done, keep reading to see my solution.