SOA PRINCIPLES :2. Service Reusability
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This document discusses the principles of service-oriented architecture (SOA). It begins with an agenda that outlines key SOA principles like standardized service contracts, service reusability, loose coupling, and others. Each principle is then discussed in more detail with sections on service reusability, standardized service contracts, and measuring service reusability. The document provides examples of how to design services for reusability and discusses how to measure actual reuse of services. It concludes with sample exam questions related to applying the principles of SOA.
SOA PRINCIPLES :2. Service Reusability
- 1. Principles OF SOAFrom knowledge To practice SUBMITTED BY : MOHAMED ZAKARYA
- 2. AGENDA Service orientation principles Standardized Service Contract Service Reusability Service Discoverability Service Composability Service Loose Coupling Service Abstraction Service Autonomy Service Statelessness Thanks
- 5. SERVICE ORIENTATION PRINCIPLES Service Reusability Service contain agnostic logic that can be position as reusable enterprise resource. Standardized Service Contract Service in same inventory are in compliance of same design service contract standards. Service Composition Services are effective composition participants. Service Discoverability Service meta data available for discoverability and interpreted. Service Loose Coupling Contract decoupled from surrounding environment. Service Autonomy Services exercise a high level of control over their underlying runtime execution environment. Service Statelessness Services minimize resource consumption , reduce state information. Service Abstraction Contract contains only essential information , that is published to consumers.
- 7. INTRODUCTION Service Reusability Service contain agnostic logic that can be position as reusable enterprise resource. Reuse in abstract : To get the most possible value out of each piece of software Software program useful for more than just one single purpose Something that is useful for a single purpose will provide value, Something that is repeatedly useful will provide repeated value and is therefore a more attractive investment. Reuse is a simple concept , but achieve reuse not easy
- 8. REUSABILITY IN REAL WORLD
- 9. INTRODUCTION
- 10. REUSE ACHIEVE SERVICE ORIENTED COMPUTING GOALS Increased Return on Investment (ROI) Services are delivered and viewed as IT assets expected to provide repeated value, that will cover exceed cost of delivery and ownership
- 11. REUSE ACHIEVE SERVICE ORIENTED COMPUTING GOALS Increased Organizational Agility Rapid delivery , New and changing business requirements can be fulfilled rapidly
- 12. SINGLE PURPOSE / MULTI PURPOSE Single purpose : Scope of usage is limited and predictable. Over time , convert into silo applications Straight forward Multi purpose : Design grows more complex Take new considerations into account Increased development effort to accommodate all of scenarios associated with range of planned capabilities
- 13. ABOUT THE PRINCIPLE Title Services are reusable Description Services contain and express agnostic logic and can be positioned as reusable enterprise resources. Goals increase ROI Increase business agility Realize agnostic service model
- 14. ABOUT THE PRINCIPLE Implementation requirements Scalable Runtime Hosting Environment Capable of high-to-extreme concurrent service usage Solid Version Control System Contracts representing reusable services Service analysts and designers with a high degree of subject matter expertise high level of service development structure the underlying logic into generic
- 16. REUSABILITY FACTORS AFFECT SERVICE DESIGN How can we design the service to best support strategic goals , vision of enterprise? Existing models, like service inventory blueprint (How does a service fit into service inventory , and how does it relate to other services?) Current business requirements & common usage scenarios (Which requirements is a service expected to fulfill , and in expected future?) Historical business patterns to predict future changes (how an organization carries out its lines of business?) Existing legacy environments & upgrade or replacement plan (What types of service adapters or wrapper services will we be forced to work with or create?) Urgency of service delivery requirements (What sacrifices will we need to make in order to fulfill high-priority tactical requirements?)
- 17. MEASURES OF PLANNED REUSE Categories such as the following can be used to refer to or label services during analysis and design phases. Tactical Reusability Targeted Reusability Complete Reusability
- 18. 1. TACTICAL REUSABILITY If project delivery requirements demand that services be developed and deployed as soon as possible , Then, Reuse efforts need to be concentrated on the immediate functional Requirements Scope of the service-oriented analysis will be limited
- 19. 2. TARGETED REUSABILITY If a project team has the ability to deliver a service with functionality that provides features beyond what is immediately required Then, adds only extensions that have the highest degree of guaranteed reuse potential Top of the list features are implemented , others added later
- 20. 3. COMPLETE REUSABILITY Based on the scope of the service boundary , equip the service with a complete range of functionality This approach is only recommended if a well-defined service inventory blueprint exists,
- 21. REUSE & AGNOSTIC SERVICES
- 22. REUSE & SERVICE INVENTORY BLUEPRINT
- 23. MEASURE ACTUAL REUSE The ultimate measure of accomplished reuse is how much a service actually is and has been used subsequent to its implementation. This can be determined by analyzing the following statistics: Allows us to judge the success of the service as an investment Ability to calculate a relatively accurate return on the cost Frequency of use The frequency with which these service consumers have used the service. Amount of Consumers The amount of service consumers that were built to use the service
- 24. SOA TERMINOLOGIES TERM Single purpose Multipurpose Agnostic Enterprise resource Entity abstraction Utility abstraction Entity service Utility service Task service Tactical reusability Target reusability Complete reusability
- 25. LOGIC CENTRALIZATION & CONTRACT CENTRALIZATION
- 26. LOGIC CENTRALIZATION & CONTRACT CENTRALIZATION Central entry points into central bodies of logic
- 27. SERVICE REUSABILITY DEMO Company have 3 legacy applications doing the following A. Application 1 1) Deal with individuals purchasing orders 2) Generate bills using individual billing Service 3) Send sms promotions 4) They can pay using sadad 5) Mobile application for there offers B.Application 2 1) Deal with suppliers , store management 2) Containers of products to sell 3) Generate billing using container billing service 4) Deal with them via mail 5) supplier financials using visa credit card C.Application 3 1) Create statistical reports ( per suppliers , individuals) for managers 2) Measure branches sales quality Please define agnostic services (entity , utility) , draw inventory blueprint , And define logic abstraction
- 28. SAMPLE EXAM QUESTIONS Q1 : . Which of the following is not a benefit associated with silo-based application design? Select the correct answer. A. The emphasis on fulfilling tactical (short-term) business requirements allows for a more predictable application delivery lifecycle. B. The analysis and design of applications are easier because strategic (long-term) business requirements don't usually need to be taken into account. C. The latest technology advancements can be leveraged by repeatedly building new applications from the ground up. D. Applications are always inherently built for repeated reuse across silos. Answer : D
- 29. SAMPLE EXAM QUESTIONS Q2 . A(n) ___________in the extent to which the Service Reusability principle is applied to a service can result in a(n) ___________in the potential for the service to be repeatedly composed. SELECT ALL THAT APPLY A. decrease, decrease B. increase, decrease C. decrease, increase D. increase, increase Answer : A,D
- 30. SAMPLE EXAM QUESTIONS Q3 . Project Team A delivered 3 services and a month later Project Team B delivered 5 services. After an audit of the services delivered by these two project teams, it was determined that 3 of the services delivered by Project Team B contained redundant logic that already resides in 2 of the services originally delivered by Project Team A. The audit results are negative because it is considered undesirable to have redundant logic among services. Which service-orientation principle could have been applied to help avoid this result? Select the correct answer. A. Service Statelessness B. Service Reusability C. Standardized Service Contract D. Service Abstraction Answer : B
- 31. SAMPLE EXAM QUESTIONS Q1 . Fill in the blank for the following definition of the Service Reusability design principle: "Services contain and express ___________logic and can be positioned as reusable enterprise resources." Select the correct answer. A. non-agnostic B. agnostic C. distinct D. new Answer : B
- 33. ANY QUESTIONS
- 34. THANKS ENJOY SOA .. WAIT FOR NEXT MAIL: ENG.MOHAMEDZAKARYA@GMAIL.COM
Editor's Notes
- #3: 6 main parts of presentation !
- #8: Several of the other principles would not exist if the service-orientation paradigm did not place reuse.
- #11: An example of the types of formulas being used to calculate ROI for SOA projects. More is invested in the initial delivery with the goal of benefiting from increased subsequent reuse
- #13: Example : for warehouse Example : for accountant Large scale : 1. Single purpose
- #14: Increase business agility : rapid fulfillment of future business automation requirements through wide-scale service composition. Enable creation of service inventories with a high percentage of agnostic services
- #15: We want services and their capabilities to be multi-purpose so that they help automate multiple business tasks.
- #18: Agnostic context , agnostic service ( entity , utility)
- #19: In this case, the scope of the service-oriented analysis will be limited to the range of features required only by the current service delivery project.
- #20: a service-oriented analysis will have been performed, and only those features at the top of the list are implemented , Others are added later,as required
- #21: Agnostic context , agnostic service ( entity , utility)
- #22: Agnostic context , agnostic service ( entity , utility)
- #23: Candidate services
- #24: This information allows us to judge the success of the service as an investment,thereby giving us the ability to calculate a relatively accurate return on the cost originally required for its delivery and on-going maintenance
- #27: Combining Logic and Contract Centralization results in the positioning of central entry points into central bodies of logic