Software Requirements Analysis and Design PDF

ACS2913 Software Requirements Analysis and Design Instructor: David Tenjo INVESTIGATING SYSTEM REQUIREMENTS THE UNIVERSITY OF WINNIPEG - ACS 2913 - FALL 2022 1 Chapter 2 Outline ▪The RMO Consolidated Sales and Marketing System Project ▪Systems Analysis Activities ▪What Are Requirements? ▪Stakeh...

ACS2913 Software Requirements Analysis and Design Instructor: David Tenjo INVESTIGATING SYSTEM REQUIREMENTS THE UNIVERSITY OF WINNIPEG - ACS 2913 - FALL 2022 1 Chapter 2 Outline ▪The RMO Consolidated Sales and Marketing System Project ▪Systems Analysis Activities ▪What Are Requirements? ▪Stakeholders ▪Information Gathering Techniques ▪Models and Modeling ▪Documenting Workflows with Activity Diagrams SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 2 Learning Objectives ❖Describe the activities of systems analysis ❖Explain the difference between functional and nonfunctional requirements ❖Identify and understand different kinds of stakeholders and their contributions to requirements definition ❖Describe information-gathering techniques and determine when each is best applied ❖Describe the role of models in systems analysis ❖Develop UML activity diagrams to model workflows SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 3 Overview Chapter 1 introduced the system development lifecycle (SDLC) and demonstrated its use for a small project This chapter expands the SDLC processes to cover a wider range of concepts, tools and techniques Systems analysis activities are detailed in this chapter A larger Ridgeline Mountain Outfitters (RMO) project is introduced that will be used throughout the text to illustrate analysis and design SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. Core process 3: Discover and understand the details of the problem or need—is the main focus of systems analysis 4 ❖RMO has an elaborate set of information systems that support operations and management Ridgeline Mountain Outfitters (RMO) ❖Customer expectations, modern technological capabilities, and competitive pressures led RMO to believe it is time to upgrade support for sales and marketing ❖A new Consolidated Sales and Marketing System was proposed ❖This is a major project that grew out of the RMO strategic planning process SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 5 RMO Information Systems Strategic Plan Technology architecture— the set of computing hardware, network hardware and topology, and system software employed by the organization SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. Application architecture—the information systems that supports the organization (information systems, subsystems, and supporting technology) 6 Supply Chain Management (SCM) • 5 years old; Java/Oracle • Tradeshow system will interface with SCM Phone/Mail Order System RMO Existing Application Architecture • 12 years old; Visual Studio/MS SQL • Reached capacity; minimal integration Retail Store System • Older package solution; minimal integration Customer Support System (CSS) • Web based system; evolved over the years, minimal integration SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 7 Proposed Application Architecture: Integrate SCM and New CSMS SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 8 Sales Subsystem New Consolidated Sales and Marketing System (CSMS) Integrates online, phone, and retail stores Order Fulfillment Subsystem Track shipments, rate products and services Customer Account Subsystem Shopping history, linkups, “mountain bucks” rewards Marketing Subsystem SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. Promotional packages, partner relationships, more complete merchandise information and reporting 9 Systems Analysis Activities The New Consolidated Sales and Marketing System (CSMS) will require discovering and understanding extensive and complex business processes and business rules The SDLC indicates the project starts with ◦ identifying the problem, ◦ obtaining approval, ◦ planning the project (as seen in Chapter 1) To get to the heart of systems analysis, details of project planning activities are omitted SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 10 Systems Analysis Activities Involve discovery and understanding SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 11 Gather Detailed Information ◦ Interviews, questionnaires, documents, observing business processes, researching vendors, comments and suggestions Define Requirements Systems Analysis Activities ◦ Modeling functional requirements and non-functional requirements Prioritize Requirements ◦ Essential, important, vs. nice to have Develop User-Interface Dialogs ◦ Flow of interaction between user and system Evaluate Requirements with Users ◦ User involvement, feedback, adapt to changes SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 12 "Requirements" in software engineering refer to a detailed description of what a software system is supposed to do, how it should behave, and what qualities or attributes it should possess. Why are requirements important? Requirements 1.Communication: Requirements serve as a common language between stakeholders, including developers, clients, and users. They ensure everyone has a shared understanding of what the software should accomplish. 2.Scope Definition: Requirements help define the scope of the project, ensuring that everyone involved knows what is in and out of scope. 3.Basis for Design: They form the foundation for the software design process, guiding developers in creating a solution that meets the specified needs. 4.Validation and Verification: Requirements provide criteria for testing and validation, ensuring that the software meets the intended goals. THE UNIVERSITY OF WINNIPEG - ACS 2913 - FALL 2016 13 requirements need to be collected, analyzed, refined, and prioritized Challenges in Managing Requirements: Managing Requirements 1.Changing Requirements: Requirements can evolve over time, so it's important to manage change effectively through processes like version control and change requests. 2.Incomplete or Inconsistent Requirements: Ambiguous or incomplete requirements can lead to misunderstandings and problems during development. 3.Managing Stakeholder Expectations: Balancing the needs and desires of various stakeholders can be challenging, and good communication skills are essential. THE UNIVERSITY OF WINNIPEG - ACS 2913 - FALL 2016 14 System Requirements • Functional requirements • Non-functional requirements Types of Requirements Functional Requirements– the activities the system must perform • Business uses, functions the users carry out • Shown as use cases in Chapter 1 Non-Functional Requirements– other system characteristics • Constraints and performance goals SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 15 Functional requirements Usability requirements FURPS+ Requirements Acronym Reliability requirements Performance requirements Security requirements + even more categories… SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 16 FURPS+ Requirements Acronym SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 17 Design constraints – ◦Specific restrictions for hardware and software Implementation requirements Additional Requirements Categories ◦Specific languages, tools, protocols, etc. Interface requirements ◦Interface links to other systems Physical requirements ◦Physical facilities and equipment constraints Supportability requirements ◦Automatic updates and enhancement methods Stakeholders Who do you involve and talk to? Stakeholders– persons who have an interest in the successful implementation of the system Internal Stakeholders– persons within the organization External stakeholders – persons outside the organization Operational stakeholders – persons who regularly interact with the system Executive stakeholders– persons who don’t directly interact, but use the information or have financial interest SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 19 Stakeholders comprehensive accounting system for public company SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 20 Phone/mail sales order clerks Warehouse and shipping personnel Stakeholders For RMO CSMS Project Marketing personnel who maintain online catalog information Marketing, sales, accounting, and financial managers Senior executives Customers External shippers (e.g., UPS and FedEx) SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 21 RMO Internal Stakeholders SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 22 Summary Systems analysis activates correspond to the core SDLC process Discover and understand details System projects originate from the information system strategic plan, which contains an technology architecture plan and an application architecture plan The RMO CSMS Project will be used throughout the text as an example of analysis and design SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 23 Summary Systems analysis involves defining system requirements– functional and non-functional Analysis activities include ◦ ◦ ◦ ◦ ◦ Gather detailed information Define requirements Prioritize requirements Develop user-interface dialogs Evaluate requirements with users FURPS+ is the acronym for functional, usability, reliability, performance, and security requirements SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 24 Summary Stakeholders are the people who have an interest in the success of the project There are internal vs. external stakeholders and operational vs. executive stakeholders SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION - CHAPTER 2 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED. 25