4.Lect-4 Decision Table Training Session

8/2/2019 4.Lect-4 Decision Table Training Session

1/16

A useful testing technique and more

Mohit Arora

Lecturer , LIECA

LPU


2/16

Definition Application areas Steps to create a

decision table Exercise Solution to exercise

2


3/16

Decision tables are used to layout in tabular form allpossible situations which a

business decision mayencounter.

A decision table lists causesand effects in a matrix.Each column represents a

unique combination. Purpose is to structure logic

3

Cause = condition

Effect = action = expected results

Causes Values 1 2 3 4 5 6 7 8

Cause 1 Y, N Y Y Y Y N N N N

Cause 2 Y, N Y Y N N Y Y N NCause 3 Y, N Y N Y N Y N Y N

Effects

Effect 1 X X X

Effect 2 X X X

Combinations


4/16

Consists of three parts Condition stubs

Lists condition relevant to decision

Action stubs Actions that result from a given set of conditions

Rules

Specify which actions are to be followed for a given setof conditions

4


5/16


6/16

1. List all causes in the decisiontable

2. Calculate the number of possiblecombinations

3. Fill columns with all possiblecombinations

4. Reduce test combinations5. Check covered combinations6. Add effects to the table

6


7/16

Hints: Write down the values

the cause/conditioncan assume Cluster related causes Put the most

dominating cause first Put multi valued

causes last

7

Causes Values 1 2 3

Cause 1 Y, N Y Y Y

Cause 2 Y, N Y Y N

Cause 3 Y, N Y N Y

Effects

Effect 1 X

Effect 2 X

Com


8/16

If all causes are simply Y/Nvalues:

2number of causes

If 1 cause with 3 values and 3with 2:31 * 23 = 24

Or, use the Values columnand multiply each valuedown the column, eg.3*2*2*2=24

8

Number of Values to

the power of the

number of causes

with these values


9/16

Algorithm:

1. Determine Repeating Factor (RF):

divide remaining combinations by thenumber of possible values for thatcause

2. Write RF times the first value, then

RF times the next etc. until row is full3. Next row, go to 1.

9

s Values 1 2 3 4 5 6 7 8

1 Y, N Y Y Y Y N N N N

2 Y, N Y Y N N Y Y N N

3 Y, N Y N Y N Y N Y Ns

1 X X X

2 X X X

Combinations


10/16

Find indifferentcombinations placea -

10

Causes Values 1 2 3 4 5 6 7 8

Cause 1 Y, N Y Y Y Y N N N N

Cause 2 Y, N Y Y N N Y Y N N

Cause 3 Y, N Y N - - Y N Y NEffects

Effect 1 X X X

Effect 2 X X X

Combinations

Causes Values 1 2 3 4 5 6 7

Cause 1 Y, N Y Y Y N N N N

Cause 2 Y, N Y Y N Y Y N N

Cause 3 Y, N Y N - Y N Y N

Effects

Effect 1 X X

Effect 2 X X X

Combinations

Join columns wherecolumns are identical

Tip: ensure the effectsare the same


11/16

Checksum For each column calculate the

combinations it represents A - represents as many

combinations as the cause has Multiply for each - down the

column

Add up total and compare withstep 2

11

Causes Values 1 2 3 4

Cause 1 Y, N Y Y Y N

Cause 2 Y, N Y N N -

Cause 3 Y, N - Y N -

Effects

Effect 1 X X

Effect 2

Checksum 2 1 1 4 8

Combinations


12/16

Read column bycolumn and

determine theeffects

One effect can occurin multiple test

combinations

12

Causes Values 1 2 3 4

Cause 1 Y, N Y Y Y N

Cause 2 Y, N Y N N -

Cause 3 Y, N - Y N -

Effects

Effect 1 X X

Effect 2 X X

Checksum 2 1 1 4 8

Combinations


13/16

A marketing company wishes to construct a decisiontable to decide how to treat clients according to threecharacteristics: Gender, City Dweller, and age group:

A (under 30), B (between 30 and 60), C (over 60). Thecompany has four products (W, X, Y and Z) to testmarket. Product W will appeal to female city dwellers.Product X will appeal to young females. Product Y will

appeal to Male middle aged shoppers who do not livein cities. Product Z will appeal to all but older females.

13


14/16

--Identify Conditions & ValuesThe three data attributes tested by the

conditions in this problem are1. gender, with values M and F;2. city dweller, with value Y and N; and3. age group, with values A, B, and C as stated

in the problem.

14


15/16

2. Compute Maximum Number of Rules Themaximum number of rules is 2 x 2 x 3 = 12

3. Identify Possible Actions The four actions are:market product W, market product X, marketproduct Y, market product Z.

4. Enter All Possible Rules The top of the tablewould look as follows: Note that allcombinations of values are present.

15


16/16

16

4.Lect-4 Decision Table Training Session

Documents

Transcript of 4.Lect-4 Decision Table Training Session