Modeling Process Chapter 2 Quiz

Chapter 2: Modeling the Process and Life Cycle

• This chapter introduces software engineering concepts related to modeling the process and life cycle of software development.
• A process encompasses a series of steps (involving activities, constraints, and resources) that produce a specific output.
• Processes involve tools and techniques.
• Processes are characterized by: prescribing activities, using resources, producing products, potentially comprising sub-processes, possessing entry/exit criteria, and being organized sequentially with clear timing.
• Processes also involve guiding principles (including goals) and constraints (applicable to activities, resources, or products).
• Processes are important for consistent and structured activities, facilitating understanding, control, improvement and capturing experience.

Chapter 2 Objectives

• Defining the meaning of a "process"
• Describing different models of the software development process
• Listing tools and techniques for process modeling

2.1 The Meaning of Process

• A process is a sequence of steps involving activities, constraints, and resources to produce a desired outcome.
• A process includes a set of tools and techniques.

2.1 Process Characteristics

• A process dictates all major activities.
• Resources are used, subject to constraints (like scheduling).
• It outputs intermediate and final products.
• It can be made up of sub-processes with a hierarchy or links between them.
• Each activity has entry and exit criteria.
• Activities follow a sequence for clear timing.
• Processes have guiding principles, including goals for each activity.
• Constraints can apply to activities, resources, or products.

2.1 Importance of Processes

• Impose structure and consistency on a set of activities.
• Lead to understanding, control, examination, and improvement of the activities.
• Allow capturing experiences and passing them forward.

2.2 Software Process Models

• Reasons for modeling a process: To form a shared understanding; identifying inconsistencies, redundancies, or omissions; evaluate suitable activities for goals; and customizing general processes for specific situations.

2.2 Software Life Cycle

• When a process involves software construction, it's often referred to as the software life cycle.
• Stages in a software life cycle: requirement analysis & definition; system design; program design; coding/implementation; testing; system delivery (deployment); and maintenance.

2.2 Software Development Process Models

• Waterfall model
• V model
• Prototyping model
• Operational specification
• Transformational model
• Phased development (incremental & iterative)
• Spiral model
• Agile methods

2.2 Waterfall Model

• One of the earliest process models.
• Suitable for well-defined problems with stable requirements.
• Straightforward and easily explainable to customers.
• Presents a high-level view and a sequence of activities.
• Each phase is marked by milestones and deliverables (artifacts).
• Sequential phases: Requirements Analysis, System Design, Program Design, Coding, Unit & Integration Testing, System Testing, Acceptance Testing, Operation & Maintenance.
• No iteration.

2.2 Waterfall Model Drawbacks

• No guidance for handling changes during development (assumes static requirements).
• Treats software development as a manufacturing process, not a creative process.
• No iterative activities.
• Long wait time before the final product.

2.2 Waterfall Model with Prototype

• A partial implementation used for better understanding of requirements and features.
• Allows for assessment of various design strategies.
• Useful for verification and validation.

2.2 V Model

• A variation of the waterfall model.
• Testing activities are mirrored against each development phase (e.g., unit testing for procedural design).
• Suitable for projects where comprehensive verification and validation are crucial.
• Re-executability of previous development stages on the left side is possible if problems arise during verification or validation.

2.2 Prototyping Model

• Allows repeated examination of requirements or design.
• Reduces risk and ambiguity in development.
• Prototypes are iteratively revised based on customer feedback.

2.2 Operational Specification Model

• Requirements are examined and their implications considered early.
• Functionality and design are integrated.

2.2 Transformational Model

• Few major development steps.
• Converts specifications into a deliverable system through a series of transformations.
• Relies on formalism and formal specifications for transformations.
• Stages: compare with requirements, formal specification, transform 1, transform 2, transform N, test, and deliver system.

2.2 Phased Development: Increments and Iterations

• Shorter development cycles.
• Systems are delivered in increments.
• Allows users to have some functionality while the rest is developed.
• Allows parallel development and use.

2.2 Spiral Model (Boehm, 1988)

• Iterative risk-driven model.
• Each iteration is a circuit around four activities: Plan (defining goals, alternatives, and constraints); Evaluate (alternatives and risks); Develop and test.

2.2 Agile Methods

• Focuses on flexibility and rapid software delivery.
• Agile Manifesto values individuals and interactions, working software, customer collaboration, and responding to change.
• Emphasizes flexibility and adaptation during development
• Common Agile methods include XP, Crystal, Scrum, and ASD.

2.2 Extreme Programming (XP)

• Emphasizes agility through communication, simplicity, courage, and feedback.
• XP includes twelve facets that define the practice.

2.3 Tools and Techniques for Process Modeling

• Notation depends on the model's purpose.
• Two major categories: static models (depicting the process); dynamic models (enacting the process).
• Static modeling elements: Activity, Sequence, Process Model, Resource, Control, Policy, Organization.
• An example of a template used in static modeling is the Artifact Definition Template.
• Dynamic modeling enables process enactment, simulating scenarios, and making improvements.
• An example of a dynamic modeling tool is a systems dynamics model.
• System dynamics models help visualize factors affecting productivity.

2.4 Practical Process Modeling

• Desirable properties of process modeling tools and techniques include fostering human understanding and communication, supporting improvement, aiding management, providing automated guidance, and supporting automated execution.

2.5 Information System Example (e.g., Piccadilly System)

• Risk analysis aspects: Probability (likelihood of a problem) and Severity (impact on the system).
• Risk is considered an artifact that needs description in the process model (i.e., risk identification, assessment, mitigation)

2.5 Unified Modeling Language (UML)

• A standardized visual language for software systems.
• Used to visualize, specify, construct, and document system structure and behavior.
• Examples of UML diagrams include use case diagrams, class diagrams, sequence diagrams, and activity diagrams.

2.7 What this Chapter Means for You

• Process development includes activities, resources, and the final product.
• Process models encompass various perspectives (organizational, functional, behavioral).
• Process models aid team behavior, coordination, and collaboration.