Nowadays, the needs and variations of software increases continuously. There is a concept that aims to produce many variations of a product called Software Product Line (SPL). The SPL concept is applied to a modeling language called Abstract Behavioral Specification (ABS). ABS can facilitate the development of many related products from one single code base. One part of the ABS language is the Product Selection Language (PSL). Using PSL, a product is expressed by a set of features. Even though some products might share some features, using PSL, all features in a product need to be stated one by one. If the product is derived from dozens to hundreds of features, defining the product will be difficult and inefficient. Therefore, the author implements a solution so that ABS developers can develop products by combining other products. These combinations are expressed using product expressions. In this research, the author extended PSL by implementing and testing product expressions in the ABS compiler front-end. In addition, the author conducted a case study with a Charity Organization System, which was developed at the RSE Research Lab in the Faculty of Computer Science at Universitas Indonesia. Keywords: Software Product Lines (SPL), Abstract Behavioral Specification (ABS), Product Selection Language (PSL), Product Expressions

1. January 2016
Extending the Product Selection Language
of the Abstract Behavioral Specification
(ABS) with Product Expressions
By: Triando 1206237265 | Advisor: Dr. Ade Azurat and Dr. Radu Muschevici
Bachelor Thesis

2. Outline
Introduction1
2
3
4
5
6 Conclusion
Abstract Behavioral Specification (ABS)
Implementation and Testing
Case Study
Discussion of Results

3. 1.
Introduction
1 2 3 4 5 6
●Motivation: Case Study
●Research Questions
●Research Goals, Scope, Limitation and Benefits

4. 1. Introduction 2. 3. 4. 5. 6.
Motivation
Issues
 Increase of software demand
 Various types of requirements
Software Product Lines (SPL)
Challenges [9]
 Minimum effort
 Shorter developments of time
Abstract Behavioral Specification (ABS)
 Product Selection Language (PSL)
solved by
facilitated by

5. Case Study: Charity Organization System (1/7)
Brief Description
● COS is part of project conducted at RSE Lab Fasilkom UI [4].
● COS is a support system to assist charitable organizations
(e.g., monitoring of charitable activities) [4].
26 Features
Sekolah Bermain
Matahari
PKPU
Ramadhan for
Kids
BeriBuku
generate
five products
Sekolah Bermain
Balon Hijau
1. Introduction 2. 3. 4. 5. 6.

6. Feature Diagram
Figure 4.1: Charity Organization System - Feature Diagram
Charity Organization System (2/7)
1. Introduction 2. 3. 4. 5. 6.

7. Selected Features - Sekolah Bermain Matahari
Charity Organization System (3/7)
1. Introduction 2. 3. 4. 5. 6.

8. Selected Features - PKPU
Charity Organization System (4/7)
1. Introduction 2. 3. 4. 5. 6.

9. Selected Features - Ramadhan for Kids
Charity Organization System (5/7)
1. Introduction 2. 3. 4. 5. 6.

10. Selected Features - BeriBuku
Charity Organization System (6/7)
1. Introduction 2. 3. 4. 5. 6.

11. Selected Features - Sekolah Bermain Balon Hijau
Charity Organization System (7/7)
1. Introduction 2. 3. 4. 5. 6.

12. Problem and Proposed Solution
1. Introduction 2. 3. 4. 5. 6.
Problem
In larger projects, a product can consist of many features from dozens to hundreds.
Consequences
Difficult & inefficient to declare products.
• Repetitive
• Large & confusing
Solution Idea
Declare product based on already
existing product.
Product Expressions
• The products can be derived from
a combination of other products.
• Manage combinations of products
with sets of operations.

13. Research Questions
1. Introduction 2. 3. 4. 5. 6.
How to implement product expressions in the Product
Selection Language (PSL) in the ABS compiler front-end?
1
2 What are the advantages and disadvantages of product
expressions in the PSL of the ABS?

14. Research Goals, Scope and Benefits
1. Introduction 2. 3. 4. 5. 6.
Research Goals The Scope of Research Limitation
1. To extend the PSL with
product expressions.
1. Implementation in the
ABS compiler front-end.
The small size of the case
study is used to validate the
implemented ABS language
extension.
2. To show that product
expressions can be useful
for ABS developers.
2. Analyzing the use of
Charity Organization
System (COS).
Benefits of Research
1. To introduce the extended PSL that can be used to
state products from combination of other products.
2. To contribute the extended PSL to the ongoing
development of ABS.
gives

15. ●Product Lines Engineering with ABS
●The ABS Compiler Front-end
1 2 3 4 5 6
2.
Abstract Behavioral Specification (ABS)

16. 1. 2. Abstract Behavioral Specification (ABS) 3. 4. 5. 6.
Product Lines Engineering with ABS (1/3)
▷ Product Selection Language (PSL)
▷ Feature Model
▷ Delta Modeling
▷ Product Line Configuration
→ product definitions [10]
→ feature hierarchy [11]
→ deltas implement features [11]
→ configures of product line [11]
Product Lines Engineering

17. 1. 2. Abstract Behavioral Specification (ABS) 3. 4. 5. 6.
Feature Model Product Selection Language (PSL)
the products
stated in
features
described in
Listing 2.2: Account PSL [11]
Figure 2.3: Account - Feature Diagram [11]
Product Lines Engineering
Product Lines Engineering with ABS (2/3)

18. 1. 2. Abstract Behavioral Specification (ABS) 3. 4. 5. 6.
the products
stated in
implement
by
Product Expressions
Product Lines Engineering
Product Selection Language (PSL)
Product Lines Engineering with ABS (3/3)
Example:
● Product P1 has features A, B, C, D.
● Product P2 is P1 without feature B, and additional features E, F.

19. 1. 2. Abstract Behavioral Specification (ABS) 3. 4. 5. 6.
The ABS Compiler Front-end (1/4)
ABS Source
Code
Concrete
Syntax
JastAdd
Listener
Abstract Syntax
Tree (AST)
parses
Figure 3.13: Flow of the Parsing Process
assigns values with
processes to AST and JastAdd

20. 1. 2. Abstract Behavioral Specification (ABS) 3. 4. 5. 6.
implement
by
Product Expressions
Product Selection Language (PSL)
using
technologies
 Another Tool for Language Recognition (ANTLR)
 Abstract Syntax Tree (AST)
 JastAdd
is parser for the compiler [14]
defines class structure for the compiler [12]
adds methods to the classes [12]
The ABS Compiler Front-end (2/4)

21. 1. 2. Abstract Behavioral Specification (ABS) 3. 4. 5. 6.
Another Tool for Language Recognition (ANTLR)
The ABS Compiler Front-end (3/4)
Example of the Choice:
1 = 2
parse
Example of the Sequence:
1,2,3,4,5
parse
Example of the Nested Phrase:
while(expr){
while(expr){...}
}
parse
Listing 2.4: Concrete Syntax - Sequence [14]
Listing 2.5: Concrete Syntax - Choice [14]
Listing 2.6: Concrete Syntax - Nested Phrase [14]
ANTLR is a parser for the compiler [14]

22. 1. 2. Abstract Behavioral Specification (ABS) 3. 4. 5. 6.
Abstract Syntax Tree (AST) and JastAdd
● AST defines class structure for the compiler [12].
● JastAdd adds methods to the classes [12].
Listing 2.7: Abstract Grammar of Tiny.ast [12]
generates
Listing 2.8: Generated Classes from Tiny.ast [12]
Listing 2.9: Add Method run() to Block class
The ABS Compiler Front-end (4/4)

23. 3.
Implementation and Testing
●Original Product Selection Language (PSL)
●Extending the PSL with Product Expressions
1 2 3 4 5 6

24. 1. 2. 3. Implementation and Testing 4. 5. 6.
Concrete Syntax of Product
Listing 3.17: Example of the PSL
parse
Listing 3.16: Concrete Syntax - Product
Original Product Selection Language (PSL) (1/2)

25. 1. 2. 3. Implementation and Testing 4. 5. 6.
Abstract Grammar of Product
Listing 3.18: Abstract Grammar - Product
Listing 3.20: JastAddListener - Product
Original Product Selection Language (PSL) (2/2)
Listing 3.16: Concrete Syntax - Product

26. 1. 2. 3. Implementation and Testing 4. 5. 6.
Extending the PSL with Product Expressions (1/9)
Operation Usage
Set Intersection operand ‘&&’ operand
Set Union operand ‘||’ operand
Set Difference operand ‘-’ operand
Parenthesis ‘(‘ operand ‘)’
Operation and Operand Product Expressions
Table 3.3: Product Expressions
● Product name
● Set of features
Operand of Product Expressions:
→ e.g., P1
→ e.g., {F1, F2}
Listing 3.21: Example of the Use of the Extended SPL

27. 1. 2. 3. Implementation and Testing 4. 5. 6.
Extending the PSL with Product Expressions (2/9)
Concrete Syntax of Product Expressions
Operation Usage
Set Intersection operand ‘&&’ operand
Set Union operand ‘||’ operand
Set Difference operand ‘-’ operand
Parenthesis ‘(‘ operand ‘)’
Table 3.3: Product Expressions Listing 3.23: New Concrete Syntax - Product Expressions
● Product name
● Set of features
Operand of Product Expressions

28. 1. 2. 3. Implementation and Testing 4. 5. 6.
Extending the PSL with Product Expressions (3/9)
Concrete Syntax of Product Declaration
Listing 3.22: The Extended Concrete Syntax - Product
Listing 3.23: New Concrete Syntax - Product Expressions
So, the PSL accepts:
• Previous syntax with set of features
• New syntax with product expressions

29. 1. 2. 3. Implementation and Testing 4. 5. 6.
Extending the PSL with Product Expressions (4/9)
Abstract Grammar of Product Expressions
Listing 3.23: New Concrete Syntax - Product Expressions
Listing 3.24: Abstract Grammar - Product Expressions

30. 1. 2. 3. Implementation and Testing 4. 5. 6.
Extending the PSL with Product Expressions (5/9)
Abstract Grammar of Product Declaration
Listing 3.25: Abstract Grammar - Product Declaration
Listing 3.24: Abstract Grammar - Product Expressions

31. 1. 2. 3. Implementation and Testing 4. 5. 6.
Extending the PSL with Product Expressions (6/9)
Abstract Grammar of Compilation Unit
Listing 3.25: Abstract Grammar - Product Declaration
Listing 3.26: Abstract Grammar - Compilation Unit
Listing 3.24: Abstract Grammar - Product Expressions

32. 1. 2. 3. Implementation and Testing 4. 5. 6.
Extending the PSL with Product Expressions (7/9)
JastAdd Listener
Abstract Grammar -
Product Expressions
Abstract Grammar -
Product Declaration
Abstract Grammar -
Compilation Unit
JastAddListener.java
modify
Concrete Syntax -
Product Expressions
Concrete Syntax -
Product Declaration
Concrete Syntax -
Compilation Unit

33. 1. 2. 3. Implementation and Testing 4. 5. 6.
Extending the PSL with Product Expressions (8/9)
Evaluation of Product Expressions with JastAdd
ProductDeclaration.jadd
→ Calls evaluation method in Main.javaMain.java
→ Creates an aspect file ProductDeclaration.jadd
→ Creates evaluation method of expressions
used in

34. 1. 2. 3. Implementation and Testing 4. 5. 6.
ProductDeclaration
Test.java
creates 14
unit tests
ProductDeclaration.jadd
run
All unit tests pass
Extending the PSL with Product Expressions (9/9)
Unit Test
The unit tests aim to ensure correct implementation of:
• Original Syntax PSL.
• Extension of product expressions.

35. 4.
Case Study
●Implementation using the Original PSL
●Implementation using the Extended PSL
1 2 3 4 5 6

36. 1. 2. 3. 4. Case Study 5. 6.
Implementation using the Original PSL
Listing 4.6: The Previous PSL
Sekolah Bermain
Matahari
PKPU
Ramadhan for
Kids
BeriBuku
definition
Sekolah Bermain
Balon Hijau
definition
definition
same definition
definition

37. “Can we define products based on the
combinations of other products?
1. 2. 3. 4. Case Study 5. 6.
Yes, by using product expressions.

38. 1. 2. 3. 4. Case Study 5. 6.
Implementation using the Extended PSL (1/3)
Product Formation
Ramadhan for Kids from Sekolah Bermain Matahari
Sekolah Bermain
Matahari
Ramadhan
for Kids- Removes: Eventual
- Adds: Money, IndividualBeneficiary, District
Using the
Extended
PSL
Using the
Original
PSL
transforms

39. 1. 2. 3. 4. Case Study 5. 6.
Implementation using the Extended PSL (2/3)
Product Formation
PKPU from BeriBuku
- Removes:
Notification, IndividualDonor, Money, Item
- Adds:
Periodic, Continuous, InstitutionDonor, District, Product
BeriBuku PKPU
transforms
Using the
Extended
PSL
Using the
Original
PSL

40. 1. 2. 3. 4. Case Study 5. 6.
Implementation using the Extended PSL (3/3)
Product Formation Sekolah Bermain Balon Hijau from
Sekolah Bermain Matahari
Sekolah Bermain
Balon Hijau
Sekolah Bermain
Matahari
restate all
features
transforms
Using the
Extended
PSL
Using the
Original
PSL

41. 5.
Discussion of Results
●Results of the Case Study
●Advantages and Disadvantages of Product Expressions
1 2 3 4 5 6

42. 1. 2. 3. 4. 5. Discussion of Results 6.
Result of the Case Study
Sekolah Bermain
Matahari
PKPU
Ramadhan for
Kids
BeriBuku
Sekolah Bermain
Balon Hijau
Results of the extended PSL:
• A product can be derived from combination of other products
• Easier for the ABS developers to state a product with expressions
• The intersection operation wasn’t used in this case study
transforms transforms

43. 1. 2. 3. 4. 5. Discussion of Results 6.
Advantages and Disadvantages of Product Expressions
Advantages
● Shorter syntax
The products can be formed directly by combination of other products.
● Readability faster
The products are derived from other products that have been declared.
● Dependencies
If ABS developers need the dependencies, the expressions already
automatically follow the referenced product.

44. 1. 2. 3. 4. 5. Discussion of Results 6.
Advantages and Disadvantages of Product Expressions
● Dependencies
If ABS developers doesn’t need the dependencies, the product that
states with expressions needs to be restated.
● Complex Expressions
If products are declared with complex expressions, then it becomes
difficult to see what features are included.
● Attribute of Value Ambiguity
Evaluation of set operations does not consider the features attribute.
Disadvantages

45. 6.
Conclusion
1 2 3 4 5 6
●Implementation of Product Expressions
●Evaluation of Product Expressions
●Suggestions for Future Work

46. 1. 2. 3. 4. 5. 6. Conclusion
Conclusion (1/3)
Operation Usage
Set Intersection operand ‘&&’ operand
Set Union operand ‘||’ operand
Set Difference operand ‘-’ operand
Parenthesis ‘(‘ operand ‘)’
Table 3.3: Product Expressions
● Product name
● Set of features
Operand of Product Expressions:
Implementation of Product Expressions
1. Products declared in terms of other products.
2. Product expressions have operations and operands.
Implemented and available as part of ABS Compiler
https://github.com/abstools/abstools

47. 1. 2. 3. 4. 5. 6. Conclusion
Evaluation of Product Expressions
Conclusion (2/3)
1. More concise product declaration using product expressions.
2. Operations were used in case study were union, difference, and
parenthesis.
3. Operation was not used in case study was intersection.
4. The evaluation only used small case study, so it needs for
further evaluation.

48. 1. 2. 3. 4. 5. 6. Conclusion
Suggestions for Future Work
Conclusion (3/3)
1. The evaluation mechanism for the attributes
included in features.
2. The bigger case studies to evaluate usability of
extended PSL.

49. 1. Beribuku. http://www.beribuku.com/. [Online; accessed 1-December-2015].
2. Is4charity. https://gitlab.com/IS4Charity/FeatureDiagram/tree/master/COS. [Online; accessed 1-
December-2015].
3. Pkpu. http://www.pkpu.org/. [Online; accessed 1-December-2015].
4. Prices abs. http://rse.cs.ui.ac.id/?open=prices/index. [Online; accessed 10- December-2015].
5. Ramadhan for kids. http://ramadhanforkids.com/. [Online; accessed 1- December-2015].
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accessed 1-November-2015].
7. Sekolah bermain balon hijau. http://sbbalonhijau.tumblr.com/. [Online; accessed 1-December-2015].
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Bibliography

50. 1. Ellyza Marthadicta Noor Rachma who helped to modify design, color,
and style of the slides.
2. Antonio Presentation Template. Link:
http://www.slidescarnival.com/antonio-free-presentation-template/84
3. Logo Fakultas Ilmu Komputer Univesitas Indonesia. Link:
http://www.cs.ui.ac.id/id/wp-content/themes/csui/img/logo-ui.png
Credits

51. Thanks
Triando
1206237265
triando21@ui.ac.id
Questions & Answers