The PISA Project A Model Driven Development case study

In collaboration with The PISA Project A Model Driven Development case study Pedro J. Molina, PhD. May 19 th, 2007

Introduction Collaboration project between: Bancaja is a Spanish bank with 1000 branches across Spain Headquarters located in Valencia Capgemini is a global company with 50.000 employees providing solutions for consulting, technology & outsourcing. PISA: Architecture for software & infrastructure platform. 2007 Capgemini - All rights reserved 3

PISA Scope Migration of the Financial Terminal 2 years, 15 people involved (avg. full-time) O.S. migration in the front-end Windows NT Windows XP Windows Vista Components written in VC++, VB4. Recompiled and migrated to VC++ & C#.NET Redesign of the financial platform to take advantage of the new capabilities Family of 2500 business functions to be migrated Semi-automated tools to migrate old applications to the new model 2007 Capgemini - All rights reserved 4

Infrastructure Scope BD Back-end Back-end Host based IBM CICS system Oracle DBs Sql Server DBs 3rd parties Web Services Middle-ware Front-end Front-End 5000 computers across 1000 branches Windows XP Specialized Financial Devices Check s scanners Financial Printers 2007 Capgemini - All rights reserved 5

Goals Productivity gain Better workload variability management Technology independence Protection of the house processes and Know-How against future migration waves Reduce maintenance costs Unique IDE (integrated development environment) 2007 Capgemini - All rights reserved 7

Foundations Model Driven Development Usage of models to capture business in a declarative way Models used to lead & drive the software life cycle From analysis to implementation Models validated formally Separation of Concerns Separation of core-business from technological issues Code Generation and automated deploy Used to guarantee: No human errors, robust code Compliance with standards Controlled execution environment Reduce tampering opportunities Pragmatic approach Full 100% Code Generation seen as an utopia Looking to solve 80%-20% scenarios 2007 Capgemini - All rights reserved 9

Novak s Rule Automatic Programming is defined as the synthesis of a program from a specification. If automatic programming is to be useful, the specification must be smaller and easier to write than the program would be if written in a conventional programming language. G.S. Novak. 2007 Capgemini - All rights reserved 10

Economics of MDD Economies of Scale The condition where inputs like resources are combined to produce multiples instances of a single product. However multiple instances in SW are valueless. SW copy cost 0 Economies of Scope The condition where inputs are combined to produce different instances of products. The cost of producing them together is smaller than producing them in different production lines. Saving is achieved thanks to the reuse of common parts. 2007 Capgemini - All rights reserved 11

Domain Engineering & Software Factory Approach Domain Engineering Investment Application Development Workbench Feedback: Customer suggestions App. Engineers suggestions Application Engineering Aplications ROI 2007 Capgemini - All rights reserved 12

Model Driven Development Model / PIM Refine / Transform Design Model / PSM Applications Characteristics: Forward Engineering (no reverse engineering) Value is in the model. Code is discarded in each iteration. Technology Independent. Tools: Editors / Modelers Validators Code Generators 3Gen Development tools 2007 Capgemini - All rights reserved 13

Economics Traditional cost = N C T Domain engineering cost = I + N CF Saving S F = C T - C F 5 C T 4 C T ROI 3 C T Costs 2 C T C T I In this domain, there is an order of magnitude of 2000-2500 business applications!! 1 2 3 4 5 Family members 2007 Capgemini - All rights reserved 14

Modelling the business Aspects to be model Navigation diagrams Presentation Presentation logic Flow Mapping Service Consumption Possible representations Graphical / Visual DSL Graphical / 2D layout Textual / Grammatical based Hierarchical (tree) form Tabular form Selection: Each aspect requires an specific representation form 2007 Capgemini - All rights reserved 16

Defining the Metamodel 6 moths working with experts in the domain Studding the domain and deciding: The Variable part To be modelled The Immutable part To be incorporated in the runtime Trade-off between Parameterization vs Standardization Lo bueno, si breve, dos veces bueno. B. Gracián, (XVII) Everything should be as simple as possible, but no simpler. A. Einstein, (XX) 2007 Capgemini - All rights reserved 17

Solution Solution provided Design of the new platform Component Migration Development of the new components Design and implementation of an specification for all business functions based on XML, Schema and a tailored abstract-action language. Design and implementation of a full DSL language workbench for specifying business functions independently of the implementation technology Design and implementation of a code generation to produce the working implementation over the platform. Implementation of semi-automatic migration tools to help in the transition between models. 2007 Capgemini - All rights reserved 18

Technology Platform.NET Platform, C# and Interop to legacy C++ DLL Application Workbench Visual Studio (full integration) MS DSL Tools Custom parser for a customized language (Antlr based) Extension Packages to provide Custom Parsing in VS2005 Code generator implemented in C# Generates 100% of code. Fully automated. No manual code is allowed to be inserted in the implementation 2007 Capgemini - All rights reserved 19

Tools implemented PISA Workbench Modelling tool built on the top of Visual Studio 2005 VS extensibility, parsers, intellisense, DSL Tools PISA Validator Checks a model and reports errors & warnings PISA Code Generator Converts an specification into a 100% executable C#.NET code PISA Runtime Components and helper libraries to support the runtime enviroment 2007 Capgemini - All rights reserved 21

MS DSL Tools In beta for 2 years Version 1.00 released in September 2006 Early adopters, but not sure about it feasibility till v. 1.0 Now already integrated into the solution Used for designing the User Interface navigation of the business application in terms of views and navigation. DSL has a moderate/high learning curve. Once learned it is productive to build new diagrams. 2007 Capgemini - All rights reserved 22

In collaboration with Demo Recording: Modelling a simple Business Function

Problems 1/3 People reluctant to change Part of the traditional programmers feel conformable and productive with their current tools. They are experts in such tools and are reluctant to change to a new work method. How to address it Involve them in the design Show the benefits of the new approach Educate the developers to be able to take full advantage of the new system 2007 Capgemini - All rights reserved 31

Problems 2/3 Code escapes The platform is closed enough to keep process under control, safety and homogeneous. However from time to time, new functionality has to be added or plugged to the system. The system should be ready to incorporate these extensions quickly. Otherwise, creative programmers will be tempted to by-pass the platform and add manual code in the wrong place. How to address it Have a dedicated team to study & implement new functionality required not present in the current system Give high priority to extensions to the platform without equivalents workarounds 2007 Capgemini - All rights reserved 32

Problems 3/3 Debugging tools A MDD approach raises the abstraction level from code to a conceptual one. Debugging ideally should be done at such conceptual level. How to address it With the actual technology, this is a hard topic to provide and implement. However animators, interpreters and model checkers could be helpful in the task. Generate clean and traceable source code. This allows easy debugging in an environment with all this capabilities. 2007 Capgemini - All rights reserved 33

Benefits Increased Quality Less coding errors Compliance with standards assured by a generator Increased Productivity Migration cost to incoming technologies will considerably be reduced. Unique integrated development environment (IDE) Covering Modelling, Debugging, Versioning & Deployment 2007 Capgemini - All rights reserved 35

Benefits Know-How captured in two orthogonal levels: Business Know-How: captured in form of specifications: isolated from technological issues Technological Know-How: captured in form of best practices and code patterns in the code generator. 2007 Capgemini - All rights reserved 36