Enterprise Information Systems Architecture (ISA) Modeling Roadmap Definitions ISA domains & levels ISA analysis techniques Review questions 4

Definition 0: Information Systems Architecture in Enterprise Architecture Business Business Model Organization Model Information Systems Applications Data Technology ISA partly stems from and partly overlaps with Business Architecture The main contact point are Business Processes (BP) Indeed most requirements for ISA come from BP, e.g. what transactions and reports the information systems should process Therefore most requirements analysis techniques cover both BP and information analysis

Definition 1 : User Requirements (UR) ISA is based on User Requirements (UR) UR reflect the needs of the users on three main domains, namely the interface of the users with a computer system the information the users handle the logic / rules and the flow of activities the users perform UR are a higher abstraction level of systems / processing requirements that are usually described by UML

Definition 3: User Needs (UN) “User Needs” (UN) are what users should get from a system “User requirements” (UR) describe what the system should do (hopefully consistently with needs) regardless its implementation There are some critical points in UN Seldom users know what they want and even less frequently know how to represent it in a useful form for software development Therefore : Needs should be elicited i.e. the user should be guided to express his/her own view of needs Requirements should be obtained by transforming and/ or mapping of the user’s view in a systems analysis view Requirements should be compared against a best practice or reference model We call this approach «Functional analysis»

Definition 4: Functional Analysis (FA) Identification of the structure of an object or of a statement through the decomposition of an object in smaller parts according to a predefined rule = structure Origin of term: it dates back to the “Analytica Priora”, where Aristotle introduces syllogistic method, argues for correctness, and discusses inductive inference. Information system: a system of functions that collect, process, store and distribute information Function: An activity with an outcome Example in Information Systems: “read” Functional analysis of information systems: Scope: defines the functions of an information system according to a given model Purpose: defines what the system should do (i.e. the functions) regardless the implementation technology

Definition 2 : Requirements analysis (Wikipedia 2012) In systems engineering and software engineering, encompasses those tasks that go into determining the needs or conditions to meet for a new or altered product, taking account of the possibly conflicting requirements of the various stakeholders, such as beneficiaries or users. It is an early stage in the more general activity of requirements engineering which encompasses all activities concerned with eliciting, analyzing, documenting, validating and managing software or system requirements. Requirements analysis is critical to the success of a systems or software project. Requirements should be documented, actionable, measurable, testable, traceable, related to identified business needs or opportunities, and defined to a level of detail sufficient for system design.

Enterprise Information Systems Architecture (ISA) Modeling Roadmap Definitions ISA domains & levels ISA analysis techniques Review questions 4

ISA modelling levels Layer Target Notations Explanation ASL Aggregate Strategic Aggregate needs List / Grid Needs are aggregate and expressed by simple notations, as grids or lists RSL Rich Semantic Layer Detailed needs Diagrams Specification languages Needs are detailed and expressed by diagrams RSL is conceptual and neglects the implementation of requirements SEI Software Engineering Interface Software Diagrams Specification & programming languages Transforms RSL into a notation targeting software engineers In most cases such notation is executable.

ISA modelling domains The analysis should cover the aspects of the system the users perceive, that we term as “domains”. Domain Explanation Information Describes the structure and properties of the information the system shall use (database) Process (workflow) Describes the workflow of the business processes and related execution rules User interface Describes the user interface, through which information is distributed to (or collected from) users.

ISA modelling grid Analysis Layer Analysis Domain Information Business functions User Interface ASL Business Information Models Business models (e.g. financial mathematical models; KPI) Stakeholder / Goal Oriented Conceptual Models ESL Conceptual Information Models UML & BPMN (flow intensive systems) SEI Implementation Frameworks / Platforms Implementation Frameworks / Platforms GUI Implementation Frameworks/ Platforms

Enterprise Information Systems Architecture (ISA) Modeling Roadmap Definitions ISA domains & levels ISA analysis techniques Review questions 4

ASL / information: SIRE Analysis Layer Analysis Domain Information Process User Interface ASL RSM SEI SIRE (Strategic Information Requirements Elicitation) is a catalog of the information domains of an enterprise. It uses a grid model, where information domains are layered into information levels, namely master information event information analytic information Developed in University of Pavia (2008) Information Domain Information Level Master Event Analysis Domain 1   …… Domain n

ASL / Process: GEF Analysis Layer Analysis Domain Information Process User Interface ASL RSM SEI GEF (General Enterprise Framework) lists the activities of business processes (BP) at the respective layers: Planning (e.g. Sales Planning) Execution (Proposal and Selling tasks) Monitoring to check execution workflow (where is the order of Mr. Smith?) Control to appraise actual results (are we on budget?) Information, to manage information collection, storage and distribution Developed in University of Pavia (2012) Layer Business Process Process 1 Process … Process N Planning   Execution Monitoring Control Information

RSM / Information: ER & DFM Analysis Layer Analysis Domain Information Process User Interface ASL RSM SEI ER (Entity Relationship) Models information at a conceptual level Not for analytic information Developed by Chen (1976) DFM (Dimensional Fact Model) Models analytic information by a specific notation. It is a conceptual technique Developed in University of Bologna (1998)

RSM / Process: BPM & UML BPMN (Business Process Management Notation) Analysis Layer Analysis Domain Information Process User Interface ASL RSM SEI BPMN (Business Process Management Notation) Models the flow of business processes. Typically a BPMN flow details a GEF quadrant. UML-EP (Unified Modeling Language with the Erikson Penker estension) It is a business oriented extension of UML, It adds models to represent the flow of a Business Process It supports the elicitation of Use Cases and Candidate Database Entities

RSM / User Interface : GOA Analysis Layer Analysis Domain Information Process User Interface ASL RSM SEI GOA (Goal Oriented Analysis) The analyst identifies the goals of each user class and the actions implied on the system Actions are candidate use cases It is a conceptual technique Developed in Politecnico di Milano (2004)

SEI level Analysis Layer Analysis Domain Information Process User Interface ASL RSM SEI SEI (Software Engineering Interface) is the final transformation stage, into which conceptual notations are transformed into executable languages. Various modeling techniques BPEL (Business Process Executive Language) for workflow implementation UML (Unified Modeling Language) for object oriented development (Class Diagrams & Use Cases) Relational model for databases and data warehouses

Enterprise Information Systems Architecture (ISA) Modeling Roadmap Definitions ISA domains & levels ISA analysis techniques Review questions 4 18

Review questions Preliminary definitions Modeling grid May an individual i belong to different classes A, B, C ? In which case yes and in which not? Consider a simple class e.g. a Volkswagen Golf What is an individual of Volkswagen Golf class? What is a specialization of Volkswagen Golf? Is Volkswagen Golf an aggregation of Engine, Car-body etc.? Describe the overall model taxonomy Describe constructions types and interpretation of Model M* Could you define a Model richer then M? Modeling grid Which are the differences between User Needs and User Requirements? Define Levels and Domains of Functional Analysis in terms of Objectives Modeling Level