Software Design Methodology

268 Chapter 9. Analysis and Evaluation of Modifiability: The SAAM Method

The interactions between scenarios are shown in Figure 10.9.

Figure 10.9 Interaction among scenarios on abstract data type architecture

10.3.4 Implicit invocation architecture

For implicit invocation architecture, scenarios 1, 2, and 3 are all direct scenarios.

Scenario 9 is also a direct scenario. The required modifications to support other

scenarios are summarised in Table 10.5.

Master Control

Text

Keyword Frequency Vector

Input

Output

Setup

Take Word

Is text empty?

Initialise

Take KWF

Is KFV empty?

Is small word

Reduce

Dictionary

List of small

words

Add Word

1, 3, 9

1

4, 6, 9

4, 6

4, 6 7

7 7

7

9

9 x 2

5

5

, 8

Software Design Methodology 269

Table 10.5 Evaluation of the implicit invocation architecture

Scenario Modification

No. Description Type Component Change

1 Extract keyword frequency

vector incrementally

Direct

2 Extract keyword frequency

vector on the whole text file

Direct

3 Extract keyword frequency

vector on demand

Direct

Insert

Delete

Take Word

4 Change the data representation

of text

Indirect

Is text empty?

To change the implementation

according to the new data

representation of text

Is small word 5 Change the data representation

of words

Indirect

Reduce

To change the implementation

according to the new data

representation of word

Insert

Delete

Take word

6 Change the data representation

of characters

Indirect

Is text empty?

To change the implementation

according to the new data

representation of characters

Add word

Delete Word

Take KFV

7 Change the data representation

of keyword frequency vector

Indirect

Is KFV empty?

To change the implementation

according to the new data

representation of KFV

8 Treat synonyms as the same

word in the extraction

Indirect Reduce Change the reduce algorithm

and the dictionary used by the

function

9 Delete and insert words from

the original text

Direct

The interactions between the scenarios are shown in Figure 10.10.