Software Process and Flows

Software Process

• A software process involves a collection of work activities, actions, and tasks performed when creating a work product.
• These activities, actions, and tasks exist within a framework or model, defining their relationships within the process.
• Framework activity is populated by software engineering actions; Each action is defined by a task set, including work tasks, products, quality assurance points, and milestones to indicate progress.

Process Flow

• Process flow describes how framework activities, actions, and tasks are organized with timeline.
• Linear process flow executes each activity sequentially.
• Iterative process flow repeats one or more activities.
• Evolutionary process flow executes activities in a circular manner, with each cycle resulting in a more complete version of the software.
• Parallel process flow executes activities concurrently.

Process Patterns

• Process patterns provide effective mechanisms for addressing problems associated with any software process
• Can be used to develop a hierarchical process description starting at a high level of abstraction
• A process pattern describes a process-related problem during software engineering work.
• Provides context about where the problem is encountered and offers proven solutions.
• Ambler created a process pattern template.

Types of Process Patterns

• Stage Pattern: Defines a problem related to a framework activity for the process, incorporates multiple task patterns relevant to that stage like Establishing Communication.
• Task Pattern: Defines a problem associated with a software engineering action or work task such as Requirements Gathering.
• Phase Pattern: Defines the sequence of framework activities within the process. Overall activity flow is iterative, some examples Prototyping or the Spiral Model.

Elements of a Process Pattern Template

• Pattern Name: A meaningful name describing the pattern within the software process(e.g., Technical Reviews).
• Forces: The environment and issues that make the problem visible are covered as well can affect its solution.
• Initial Context: the conditions under which the pattern applies such as considering activities, entry states for the process and existing software engineering.
• Problem: The specific problem the pattern solves.
• Solution: How to implement the pattern successfully.
• Resulting Context: The conditions resulting from successful pattern implementation which considers activities, exit state, and the generated information.
• Related Patterns: Related process patterns may be represented in a diagrammatic form.
• Communication encompasses the task patterns: ProjectTeam, Scope Isolation,and Scenario Creation.
• Known Uses and Examples: Specific instances where the pattern is applicable (e.g., Communication is mandatory at the start of any software project.

Process Assessment and Improvement

• Several approaches to process assessment and improvement have been created over the past few decades.
• Standard CMMI Assessment Method for Process Improvement (SCAMPI): Assessment model with five steps by starting, diagnosing, establishing, acting, and learning.
• CMM-Based Appraisal for Internal Process Improvement (CBA IPI)—Offers a diagnostic technique for assessing the relative maturity of software organizations while using the SEI CMM as the basis
• SPICE (ISO/IEC15504)—A standard defining requirements for software process assessment; Assists organizations in creating an objective evaluation of software processes.
• ISO 9001:2000 for Software is a standard that improves overall quality product, systems, or services.

Prescriptive Process Models

• These models bring order to software development and provide structure/a roadmap for teams.
• Include the waterfall model, incremental model & evolutionary model

Waterfall Model

• The waterfall model is a sequential approach to software development.
• It starts with customer requirements and goes through planning, construction, and ending with support of the software.

V-Model

• The V-model is a variation of the waterfall model, it shows the correlation between quality assurance actions and activities (communication, modeling, and early construction).
• Software teams define basic requirements, refining a V-model into detailed representations of the problem being solved.
• Moving up the right side of the V-model, teams conduct tests (quality assurance actions) to validate models that were created.

Incremental Process Model

• The Incremental process model uses linear sequences in a staggered timeline.
• Each sequence delivers software "increments" (similar to evolutionary models).
• The initial increment is often a core product, with supplementary features remaining for later increments.
• The core product is evaluated by the customer, with the next increment planned based on use and evaluation.

Evolutionary Process Model

• Evolutionary models involve over a period of time.
• These models evolve over time and are iterative, allowing development of more complete versions of the software.

Prototyping of Evolutionary Process Model

• A customer defines general objectives for software but may not specify features or functions.
• The developer might be unclear about: Algorithm efficiency, adaptability of an OS
• Prototyping can offer a relevant approach for the project.

Spiral Model

• Spiral model couples iterative prototyping with controlled aspects from the waterfall model.
• Spiral model provides potential for rapid development.

Concurrent Model

• This model allows teams to represent iterative elements from other process models.
• Modeling invokes actions like prototyping, analysis, and design.

Specialized Process Models

• Take on characteristics of traditional models.
• Applied when a specific software engineering approach is chosen.
• The component-based development model provides software reuse, reduces cycle time and project cost if component becomes routine for culture.

Formal Methods Model

• Includes the mathematical specification of the system.
• Verification of computer programs through mathematical notation.
• It eliminates issues through analysis by addressing ambiguity and inconsistency.
• Program verification is used to find the issues.

Unified Process

• Aims to use features of traditional software process models and implements agile software development principles.
• Importance of customer communication and streamlines ways to describe a system and focuses more understanding the process to be reused more.

Phases of the Unified Process

• Inception: Includes customer communication and planning; Business are identified along with a rough architecture and a plan for the iterative.
• Elaboration: Includes communications and modeling activities like expanding architectural representation of many views of the software.
• Construction: Software components either develop or get acquired; To do this software needs to reflect the project done on the phase of elaboration.
• Transition: Includes later stages of generic construction and the first step that would be the generic deployment as software is provided to the user.
• Production: Generic deployment of this generic process during the ongoing use software so defect can be easily spotted or any request can be sent out by the user.

Personal and Team Process Models

• A software process needs to adapt to the needs of project team.
• The team itself can create its own process while meeting needs as well.

Personal Software Process (PSP)

• Emphasizes personal measurement of the work with result.
• The PSP model defines five framework activities: Planning, High-level design, High-level design review, Development, Postmortem

Team Software Process (PSP)

• The goal of TSP is to a "self directed” project team that creates high-software.
• TSP Objectives: Create self-directed teams, show managers how to motivate teams
• TSP Framework Activities: Project launch, implementation, high-level, implementation, integration, postmortem.
• Their counterparts in PSP and the team can product software in measure.

Process Technology

• It helps organizations analyze work, tasks, control, and monitor progress with quality.
• Framework helps create a model.

Product and Process

• Product will be weak if the process is weak and reliance on the process is dangerous.