Applying system thinking to model-based software engineering
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This document discusses a software engineering course integrating system thinking and model-based practices at Kinneret Academic College, highlighting its development and application in undergraduate and graduate curricula. The course addresses the disconnect in understanding between software engineers and systems engineers through a structured approach using Unified Modeling Language (UML) and a life-cycle model. A case study on an automated library system, 'robolib,' illustrates practical applications of this modeling approach, emphasizing the importance of consistency across various system levels.
![Business-Level Behaviour (“Business Logic”) and its Functional
Decomposition (Activity Diagram)
[without books]
• Super-activities (yellow) = Business-Level Use cases
• Sub-activities (white) = Candidates for SWIS-Level Use Cases
© Dr. Amir Tomer
EDUCON 2012 10
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[without books]](https://image.slidesharecdn.com/tomer-educon2012-141121095154-conversion-gate02/85/Applying-system-thinking-to-model-based-software-engineering-10-320.jpg)
Applying system thinking to model-based software engineering
- 1. Applying System Thinking to Model-Based Software Engineering Amir Tomer Head, Software Engineering Department Kinneret Academic College on the Sea of Galilee, Jordan Valley, Israel [email protected] © Dr. Amir Tomer EDUCON 2012 1
- 2. The Talk • This talk is about a Software Engineering course, with Systems Engineering thinking – Developed 1999 at the CS Dept., Technion, Israel – Evolved into two main versions for two different populations • CS/SWE Undergraduate (B.Sc.) students • Systems Engineering graduate (ME) students – Was delivered in more than 50 classes – Based on industrial experience • Author’s (Lecturer’s) Background – B.Sc., M.Sc. and Ph.D. in Computer Science – Over 25 years of industrial experience in SW & Systems engineering and management – Over 17 years of academic teaching and research – Certified Systems Engineering Professional (CSEP) by INCOSE © Dr. Amir Tomer EDUCON 2012 2
- 3. The Problem • Computer Science / Software Engineering undergraduate students concentrate much on programming techniques – Not always getting the “big picture” of large industrial projects • Systems Engineering graduate students come from various engineering disciplines – Not always getting to understand the unique characteristics of software However... • Systems Engineers and Software Engineers work closely together in large industrial projects – Having difficulties in sharing a common approach © Dr. Amir Tomer EDUCON 2012 3
- 4. The Approach • Considering the entire Development Life-cycle – From highest level business logic down to detailed software design and implementation • Using a unified definition of “system” at each level of decomposition (“System-of-Interest”) – With Functional, Structural and Behavioural views • Using a unified modeling language (UML) – Selecting the most appropriate model for each view at each level • Focusing on model consistency – Between models at the same level – Between system decomposition levels © Dr. Amir Tomer EDUCON 2012 4
- 5. The Life Cycle • Systems usually evolve iteratively • Each evolution iteration goes through a (partial or full) “V” life-cycle model – During a single “V” a system is repeatedly decomposed into its sub-systems, components, etc. © Dr. Amir Tomer Level 1 Definition, Analysis & Design Integration & Testing Decomposition EDUCON 2012 5 Composition Level 0 Level n Client’s needs Product delivery
- 6. A unified approach to “System” • System – Definition* – combination of interacting elements organized to achieve one or more stated purposes • Thus, each system has the following properties – Purpose(s) – Elements, which have Functional system-of-interest Model » Organization Structural » Interaction Model Behavioural © Dr. Amir Tomer *ISO/IEC/IEEE 15288 EDUCON 2012 6 system element system element system element system element system system system system element system element system system element system element system element system system system element Model
- 7. © Dr. Amir Tomer The “Levels of Interest” of Software-Intensive System Modeling • The general definition of a “system” allows unlimited depth of hierarchical breakdown – Although this is applicable also for SWISs, there are 5 types of levels, for which certain model types are preferred for the sake of modeling effectiveness “Business” Software Intensive System (SWIS) Hardware Platforms & Devices (Hardware Configuration Items = HWCIs) These will be considered as either: - atomic elements - SWISs, requiring further breakdown Software Applications (Computer SW Configuration Items = CSCIs) Computer Software Components (CSCs) Computer Software Units (CSUs) EDUCON 2012 7 Equipment Humans Users and other Stakeholders Other SWISs
- 8. A Case Study • One of the case-studies used in the course is RoboLib: – A fully automated library, in which readers may • Borrow books for on-site reading • Order page photocopies from books • Take books home for further reading – The readers do not approach the books themselves • A robot carries out all the book conveyance inside the library • The following slides present a few examples* of models developed / discussed by the students during class tutorials * The examples do not appear in the paper. You may get them by e-mail [email protected] © Dr. Amir Tomer EDUCON 2012 8
- 9. Business-level Functional Model (Use Case Diagram) The Library (a book-loaning business) RoboLib System Initial Subscription On-site Reading Photo-copying Home Reading Reader • The RoboLib System, as well as the Robot and Photocopier “actors” are components of the business, and are shown in this diagram for clarification purposes © Dr. Amir Tomer EDUCON 2012 9 Day Closure Robot Photocopier
- 10. Business-Level Behaviour (“Business Logic”) and its Functional Decomposition (Activity Diagram) [without books] • Super-activities (yellow) = Business-Level Use cases • Sub-activities (white) = Candidates for SWIS-Level Use Cases © Dr. Amir Tomer EDUCON 2012 10 Day Closure Photo-copying Home Reading Page photocopying On-site Reading Initial Subscription library site surfing Subscription subscription complete service selection On-site borrowing On-site returning Login entrering library Logout Returning books from home exiting library Taking books home Return to storage Inv entory check end of day end of activity «datastore» Books data «datastore» Readers data [with books] [exit] [photo-copy] [borrow] [return] [with books] [without books]
- 11. Deriving SWIS-Level Functional Model (Use Cases) from the Business-Level Functional Decomposition RoboLib System Reader Subscritpion Login Page hotocopying «include» «include» «include» «include» On-site borrowing «include» On-site returning Photocopier «include» • Each Use-Case is specified in detail, either by a structured textual specification or by a behavioural model (activity diagram) © Dr. Amir Tomer EDUCON 2012 11 Return to storage Inventory check Returning books from home Taking books home Logout Robot Book conveyance Locating an available copy System System startup shutdown
- 12. SWIS-Level Structure (Deployment Diagram) • The diagram is accompanied by a nodes and interfaces specification • Structural and functional model consistency: – The left-hand side interfaces are associated with the “Reader” actor – The right-hand side interfaces are associated with the “Robot” and “Photocopier” actors © Dr. Amir Tomer EDUCON 2012 12
- 13. Software-Level (CSCI) Structure (Component Diagram) Library Software Robot Software login/logout Reader's GUI user activities Administration DB transactions «DB» Library repository DB transactions Loan services Subscription forms Conveyance requests Conveyance requests Robot location/status Photoc. status loan services Books enter/exit • The diagram is accompanied by a components and interfaces specification © Dr. Amir Tomer EDUCON 2012 13 Conveyance Robot mission management requests Basic robot operation collecting/dropping a book location/status operation commands
- 14. SWIS-Level and Software-Level Structure Consistence (Composite Structure with Ports) LAN «wireless» «delegate» loan collecting/dropping a book • Structure consistency: Internet Subscription forms Administration Conveyance requests Conveyance requests – Each port is uniquely associated with a SWIS-Level link (Deployment Diagram) – All software interfaces are delegated to / from ports © Dr. Amir Tomer EDUCON 2012 14 Library LAN Photocopier Gate Reading post Robot Barcode reader Reader's GUI user activities Loan services Photoc. status Books enter/exit Robot location/status Robot mission management Basic robot operation location/status «DB» Library repository Conveyance requests «delegate» login/logout DB transactions operation commands «delegate» services DB transactions «delegate» «delegate» «delegate» TCP/IP «delegate» «delegate» «delegate» «delegate»
- 15. Course Structure and Contents • Duration – One semester (42 academic hours) • Class Sessions – Lectures (2 h/w), demonstrated with an “elevator system” case-study – Tutorials (1 h/w), using the “RoboLib” case study • Homework (50% of final grade) – A “rolling” project, modeling a given system throughout its entire levels – Submitted in parts by teams of 3-4 member • Final exam (50% of final grade) – A multi-choice exam (30 questions / 2 hours), demanding understanding and application of the acquired knowledge © Dr. Amir Tomer EDUCON 2012 15
- 16. Students Feedback • Undergraduate (B.Sc.) CS/SWE students – Usually appreciate the course only when facing industrial practice – A common comment from students who already work: “It was the most important course during my degree” • Graduate (ME) students – Most of them are already employed as systems engineers in the industry – Many start to apply the methods in their companies during or right after the course © Dr. Amir Tomer EDUCON 2012 16
- 17. Thank you for listening! © Dr. Amir Tomer Any questions? EDUCON 2012 17
Editor's Notes
- #2: אודות הקורס