1. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 1 Software Engineering: A Practitioner’s Approach, 6/e Chapter 6 System Engineering Software Engineering: A Practitioner’s Approach, 6/e Chapter 6 System Engineering copyright © 1996, 2001, 2005 R.S. Pressman & Associates, Inc. For University Use Only May be reproduced ONLY for student use at the university level when used in conjunction with Software Engineering: A Practitioner's Approach. Any other reproduction or use is expressly prohibited.

2. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 2 System … Wazzat? A set or arrangement of things related to form a unity or organic whole A set or arrangement of things related to form a unity or organic whole A set of facts, rules, principles, etc… classified and arranged to show a logical plan linking the various parts A set of facts, rules, principles, etc… classified and arranged to show a logical plan linking the various parts A method or plan of classification or arrangement A method or plan of classification or arrangement An established method of doing something; method; procedure An established method of doing something; method; procedure

3. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 3 Computer-Based System A set or arrangement of elements organized in order to accomplish some predefined goal by processing information A set or arrangement of elements organized in order to accomplish some predefined goal by processing information

4. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 4 System Engineering Elements of a computer-based system Elements of a computer-based system Software Software Hardware Hardware People People Database Database Documentation Documentation Procedures Procedures Systems Systems A hierarchy of macro-elements A hierarchy of macro-elements

5. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 5 The Hierarchy

6. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 6 System Modeling Define the processes that serve the needs of the view under consideration. Define the processes that serve the needs of the view under consideration. Represent the behavior of the processes and the assumptions on which the behavior is based. Represent the behavior of the processes and the assumptions on which the behavior is based. Explicitly define both exogenous and endogenous input to the model. Explicitly define both exogenous and endogenous input to the model. Exogenous inputs link one constituent of a given view with other constituents at the same level of other levels; endogenous input links individual components of a constituent at a particular view. Exogenous inputs link one constituent of a given view with other constituents at the same level of other levels; endogenous input links individual components of a constituent at a particular view. Represent all linkages (including output) that will enable the engineer to better understand the view. Represent all linkages (including output) that will enable the engineer to better understand the view.

7. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 7 System Modeling Restraining factors: Restraining factors: ASSUMPTIONS reduce the number of possible permutations or variations ASSUMPTIONS reduce the number of possible permutations or variations SIMPLIFICATIONS enable to create a model in a timely fashion SIMPLIFICATIONS enable to create a model in a timely fashion LIMITATIONS help to bound the system LIMITATIONS help to bound the system CONSTRAINTS guide the manners in which a model is created and approaches taken when implementing the model CONSTRAINTS guide the manners in which a model is created and approaches taken when implementing the model PREFERENCES indicate preferred architecture for all data, functions and technology. May clash with other restraining factors PREFERENCES indicate preferred architecture for all data, functions and technology. May clash with other restraining factors

8. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 8 System Simulation Used to verify and validate models before implementing them Used to verify and validate models before implementing them Helps eliminating surprises during implementation Helps eliminating surprises during implementation Allows system engineers to “test drive” the specifications of a system Allows system engineers to “test drive” the specifications of a system

9. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 9 System Engineering Two variants exist: Two variants exist: Business Process Engineering Business Process Engineering Product Engineering Product Engineering

10. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 10 Business Process Engineering  Uses an integrated set of procedures, methods, and tools to identify how information systems can best meet the strategic goals of an enterprise  Focuses first on the enterprise and then on the business area  Creates enterprise models, data models and process models  Creates a framework for better information management distribution, and control

11. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 11 System Architectures Three different architectures must be analyzed and designed within the context of business objectives and goals: Three different architectures must be analyzed and designed within the context of business objectives and goals: Data architecture provides a framework for the information needs of a business or business function Data architecture provides a framework for the information needs of a business or business function Application architecture encompasses those elements of a system that transform objects within the data architecture for some business purpose Application architecture encompasses those elements of a system that transform objects within the data architecture for some business purpose Technology infrastructure provides the foundation for the data and application architectures Technology infrastructure provides the foundation for the data and application architectures

12. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 12 The BPE Hierarchy Information strategy planning (ISP) Information strategy planning (ISP)  strategic goals defined  success factors/business rules identified  enterprise model created Business area analysis (BAA) Business area analysis (BAA)  processes/services modeled  interrelationships of processes and data Application Engineering Application Engineering  a.k.a... software engineering  modeling applications/procedures that address (BAA) and constraints of ISP Construction and delivery Construction and delivery  using CASE and 4GTs, testing

13. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 13 Information Strategy Planning Management issues Management issues  Define strategic business goals/objectives  Isolate critical success factors  Conduct analysis of technology impact  Perform analysis of strategic systems Technical issues Technical issues  Create a top-level data model  Cluster by business/organizational area  Refine model and clustering

14. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 14 Defining Objectives and Goals Objective—general statement of direction Objective—general statement of direction Goal—defines measurable objective: “reduce manufactured cost of our product” Goal—defines measurable objective: “reduce manufactured cost of our product”  Subgoals:  decrease reject rate by 20% in first 6 months  gain 10% price concessions from suppliers  re-engineer 30% of components for ease of manufacture during first year Objectives tend to be strategic while goals tend to be tactical Objectives tend to be strategic while goals tend to be tactical

15. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 15 Business Area Analysis Define “naturally cohesive groupings of business functions and data” (Martin) Define “naturally cohesive groupings of business functions and data” (Martin) Perform many of the same activities as ISP, but narrow scope to individual business area Perform many of the same activities as ISP, but narrow scope to individual business area Identify existing (old) information systems / determine compatibility with new ISP model Identify existing (old) information systems / determine compatibility with new ISP model  Define systems that are problematic  Defining systems that are incompatible with new information model  Begin to establish re-engineering priorities

16. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 16 The BAA Process sales acct manufacturing QC eng’ring distribution admin. Data Model Process Decomposition Diagram Matrices e.g., entity/process matrix Process Flow Models

17. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 17 Product Engineering

18. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 18 Product Architecture Template (after Hatley-Pirbhai)

19. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 19 Architecture Flow Diagram

20. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 20 System Modeling with UML Deployment diagrams Deployment diagrams Each 3-D box depicts a hardware element that is part of the physical architecture of the system Each 3-D box depicts a hardware element that is part of the physical architecture of the system Activity diagrams Activity diagrams Represent procedural aspects of a system element Represent procedural aspects of a system element Class diagrams Class diagrams Represent system level elements in terms of the data that describe the element and the operations that manipulate the data Represent system level elements in terms of the data that describe the element and the operations that manipulate the data These and other UML models will be discussed later

21. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 21 Deployment Diagram

22. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 22 Activity Diagram

23. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 23 Class Diagram