Equivalence Class Testing- Next date problem

Equivalence class testing (Equivalence class Partitioning) is a black-box testing technique used in software testing as a major step in the Software development life cycle (SDLC). This testing technique is better than many of the testing techniques like boundary value analysis, worst case testing, robust case testing and many more in terms of time consumption and terms of precision of the test cases. Since testing is done to identify possible risks, equivalence class testing performs better than the other techniques as the test cases generated using it are logically identified with partitions in between to create different input and output classes. This can be shown from the next-date problem which is stated below:

Given a day in the format of day-month-year, you need to find the next date for the given date. Perform boundary value analysis and equivalence-class testing for this.

Conditions :

D:  1<Day<31
M:  1<Month<12
Y:  1800 <Year <2048 

Boundary Value Analysis:

No. of test Cases (n = no. of variables) = 4n+1 = 4*3 +1 =13 

Test Cases:

Test Case ID	Day	Month	Year	Expected Output
1	1	6	2000	2-6-2000
2	2	6	2000	3-6-2000
3	15	6	2000	16-6-2000
4	30	6	2000	1-7-2000
5	31	6	2000	Invalid Date
6	15	1	2000	16-1-2000
7	15	2	2000	16-2-2000
8	15	11	2000	16-11-2000
9	15	12	2000	16-12-2000
10	15	6	1800	16-6-1800
11	15	6	1801	16-6-1801
12	15	6	2047	16-6-2047
13	15	6	2048	16-6-2048

Equivalence Class Testing:

Input classes:

Day:
D1: day between 1 to 28
D2: 29
D3: 30 
D4: 31
Month:
M1: Month has 30 days
M2: Month has 31 days
M3: Month is February
Year:
Y1: Year is a leap year
Y2: Year is a normal year 

Output Classes:

Increment Day
Reset Day and Increment Month
Increment Year
Invalid Date

Strong Normal Equivalence Class Test Cases:

Test Cases:

Test Case ID	Day	Month	Year	Expected Output
E1	15	4	2004	16-4-2004
E2	15	4	2003	16-4-2003
E3	15	1	2004	16-1-2004
E4	15	1	2003	16-1-2003
E5	15	2	2004	16-2-2004
E6	15	2	2003	16-2-2003
E7	29	4	2004	30-4-2004
E8	29	4	2003	30-4-2003
E9	29	1	2004	30-1-2004
E10	29	1	2003	30-1-2003
E11	29	2	2004	1-3-2004
E12	29	2	2003	Invalid Date
E13	30	4	2004	1-5-2004
E14	30	4	2003	1-5-2003
E15	30	1	2004	31-1-2004
E16	30	1	2003	31-1-2003
E17	30	2	2004	Invalid Date
E18	30	2	2003	Invalid Date
E19	31	4	2004	Invalid Date
E20	31	4	2003	Invalid Date
E21	31	1	2004	1-2-2004
E22	31	1	2003	1-5-2003
E23	31	2	2004	Invalid Date
E24	31	2	2003	Invalid Date

So from this problem it is clearly seen that equivalence class testing clearly checks for many cases that boundary value did not considered like that of February which has 28-29 days, leap year which lead to variation in number of days in February and many more.

Hence the above example proves that equivalence partitioning generates more efficient test cases that should be considered during risk assessment.