This document summarizes key findings from a learning package on SOA migration. It discusses what is known from academic literature and industry surveys. From the systematic literature review, 8 families of SOA migration approaches were identified. Interviews with industry architects found that migrations in practice typically follow a "bowl-shaped" approach focused on forward engineering and wrapping existing assets. Migrations aim to enable reuse or integration and are driven by enterprise architecture.

1. S-Cube Learning Package
SOA Migration: Study of Theory and Practice
Maryam Razavian, Patricia Lago
VU University Amsterdam (VUA)
www.s-cube-network.eu

2. Learning Package Categorization
S-Cube
Engineering Principles, Techniques
& Methodologies
Designing and Migrating Service-Based Applications
SOA Migration

3. Learning Package Overview
§ Problem Description
§ What do we know in academia
– Systematic Review
§ What do we know in industry
– Industrial Survey
3

4. Migration of Legacy Systems to SOA
Migrate
Pre-existing Service-based
enterprise assets Systems
4

5. SOA Migration: Problem areas
What to do? How to do?
What activities What process
SOA
Migration
What knowledge?
What are the inputs and
outputs
These problem areas are introduced in [1]
5

6. Understanding SOA Migration using a
Framework
This framework called SOA-MF is presented in [2].
6

7. SOA-MF: Positioning and Categorizing
Approach A
Approach B
8

8. Learning Package Overview
§ Introduction on SOA Migration
§ What do we know in academia
– Systematic Review
§ What do we know in industry
– Industrial Survey
9

9. What SOA migration entails in theory
Goal: What types of SOA migration exist in the field?
§ Research Method: Systematic Literature Review
Why?
– Methodological rigor in aggregating existing SOA migration
approaches
– Minimizing the bias in review process à extraction of
sound migration categories
The details related to systematic review is published in [3]
10

10. Systematic Review Process Stages
Planning Conducting Reporting
the review the review the review
Selection of
Research Questions Search Process
Primary Studies
RQ) What methods/processes/approaches regarding legacy to SOA
migration, have been proposed in research community so far?
11

11. Review Protocol
Planning
the review
Selection of
Research Questions Search Process
Primary Studies
1. Search Query: ( migration OR …[ related terms]) AND (legacy
system OR …) AND ( SOA OR …)
2. Data Sources: digital libraries (IEEE Explore, ACM digital library, ISI
…)
3. Search Scope: titles and abstracts
12

12. Related Terms for the Keywords
SOA Legacy Migration
service oriented architecture legacy code modernization
service computing legacy system transformation
service-based existing system reengineering
service-centric existing code migrate
service engineering existing asset
Service oriented software pre-existing code
engineering
Search Query
("SOSE" OR "SOA" <or> "service computing" <or>"service based" <or> "service centric" <or>"service
engineering" <or>"service oriented " <or> "service oriented architecture" <or> "service oriented software
engineering" or "service") AND ("legacy" <or> "legacy code" <or>"legacy system" <or>"existing system"
<or>"legacy component" <or> "existing code" <or>" existing asset" <or>"existing component" <or>"pre-
existing code" <or>"pre-existing system" <or>"pre-existing component") <and>("migrate" <or> "migration"
<or>"modernization" OR "transformation" <or>"reengineering") <and> (pyr >= 2000 <and> pyr <= 2009)
13

13. Review Protocol
Planning
the review
Selection of
Research Questions Search Process
Primary Studies
Inclusion Criteria:
I1) A study that is about migration to services
I2) A study that addresses migration from pre-existing legacy assets
I3) A study that proposes a solution for migration
14

14. Review Results
Conducting 51 Primary Studies
the review
Distribution of primary studies published by year
15

15. Qualitative Data Analysis
Qualitative Data Analysis: Coding to achieve mapping on SOA-
MF
16

16. 8 families of SOA Migration
a) b) c) d)
F1)
F2)
F3)
Service Identification Family F4)
F5)
F6)
F7)
Forward Engineering with Design Element F8)
Transformation Family
17

17. What do the families imply?
1. What are general types of solution in this family?
2. To what extent the reverse engineering,
transformation and forward engineering occurs?
3. What activities are carried out?
4. What artifacts are used and produced?
18

18. How does it help?
What to do? How to do?
What activities What process
SOA
Migration
Goal: identifying the
activities that should be
covered in the migration
• What legs do I
need? What knowledge?
• What is the What are inputs and
outputs
closest family?
19

19. What types of knowledge shape
SOA migration?
Code-related Knowledge
20

20. What types of knowledge shape
SOA migration?
Design-related Knowledge
21

21. What types of knowledge shape
SOA migration?
Problem-related Knowledge
22

22. How does it help?
What to do? How to do?
What activities What process
SOA
Migration
What knowledge?
What are inputs and
outputs
23

23. SOA Migration Themes
Two different sequencing of
activities
24

24. SOA Migration Themes
Arch-shaped approaches Bowl-shaped approaches
Migration for Modernization: Migration for reuse in service-based
renovate existing system to development: facilitating reuse in
reconstitute it in new form building new service-based systems
65% 35%
25

25. How does it help?
What to do? How to do?
What activities What process
SOA
Migration
What knowledge?
What are inputs and
outputs
26

26. Learning Package Overview
§ Introduction on SOA Migration
§ What do we know in academia
– Systematic Review
§ What do we know in industry
– Industrial Survey
27

27. What SOA Migration entails in Practice?
Study: What Type of SOA Migration are You?
§ 6 different leading companies in SOA solutions participated
– SOA Migration Projects (both consultancy and in house)
– 9 interviews with senior architects (1 hour)
– Both enterprise and technical architects
The details related to systematic review is published in [4,5]
28

28. What Families Occur in Practice
29

29. SOA Migration Themes - Practice
Bowl-shaped approaches
30

30. SOA Migration Themes - Practice
1. Migration for Reuse: I want 2. Migration for Integration: I
to modernize my current want to integrate my existing
system to SOA applications using SOA
technology
+
+
SO analysis and
Wrapping the whole design drives
Temporary wrapping application (or integration
existing assets segments)
Understanding existing
business processes
31

31. What did we Learn?
1. All bowl-shaped
2. Forward Engineering leg is covered
3. Focus on top most transformation level
1. Transformation at different levels: Enterprise Architecture
Transformation, Business Process Transformation
4. Incremental SOA Migration
5. Enterprise architecture drives SOA Migration
32

32. Summary
Systematic Review Industrial Survey: What
What we know of SOA are the main types of
migration in the migration in practice, What
literature is different
33

33. References
[1] M.Razavian, D.K.Nguyen, P.Lago, Willem-Jan van den Heuvel, The SAPIENSA Approach for
Service-enabling Pre-existing Legacy Assets,International Workshop on SOA Migration and
Evolution 2010 (SOAME 2010), 2010, OFFIS
[2] M. Razavian and P.Lago, Towards a conceptual framework for legacy to SOA migration, 5th
International Workshop on Engineering Service Oriented Applications (WESOA) at ICSOC, 2009,
pp. 15.
[3] M. Razavian, P. Lago, A frame of reference for SOA migration, Springer LNCS 6481,
Servicewave , 2010.
[4] M. Razavian and P. Lago, A survey of SOA migration in industry, in International Conference on
Service Oriented Computing, ICSOC, 2011.
[5] M. Razavian and P.Lago , A lean and mean SOA migration strategy, Under submission, 2012, p.
10