Draft:Object Life Cycle Diagram

An Object life cycle diagram (OLCD) is a graphical representation that illustrates the various states an object undergoes during its existence and the transitions between those states. It is widely used in object-oriented analysis and design to model the dynamic behavior of objects in a system. By emphasizing state changes, OLCD helps capture how an object evolves in response to specific events, reflecting real world business processes or domain requirements.

This diagram can be expressed in different notation languages. For instance, Unified Modeling Language (UML) provides state diagrams to represent changes in object states Various software engineering methodologies, including the Methodology for Modeling and Analysis of Business Processes (MMABP), leverage OLCD to align the static definition of objects with dynamic process flows, thereby ensuring consistency across an entire system.

Notations

Unified Modeling Language (UML)

Unified Modeling Language (UML) is a standardized graphical language used to visualize, specify, construct, and document the artifacts of software-intensive systems. It provides a rich set of modeling elements to represent both the structure and behavior of a system. UML supports the entire software development lifecycle, ensuring consistency and traceability from design to implementation.

When it comes to modeling the object life cycle, UML provides the following key diagrams:

• State diagram (main diagram): Captures the dynamic behavior of an object by representing its states, events triggering transitions, and the transitions themselves.
• State machine diagram (alternative diagram): A specific implementation of Statecharts within UML, extending the capabilities of traditional state diagrams by incorporating hierarchical states, parallel states, and event-driven transitions. State Machine Diagrams are particularly useful for modeling complex object life cycles, as they can depict nested states, concurrent behaviors, and guard conditions.

These diagrams provide complementary views, allowing for a comprehensive representation of an object's behavior within the system.

Modeling object life cycle

Methodology for modeling and analysis of business processes (MMABP)

The object life cycle diagram provides a complementary perspective on the entire system. According to the MMABP methodology, the business system model consists of four components:

• Process map (TOGAF event diagram)
• Process flow model (BPMN)
• Model of concepts (UML class diagram)
• Object life cycle model (State diagram)

All components must be consistent with one another and work together seamlessly. The object life cycle model does not describe real-world behavior but serves as a detailed ontological model.

The Methodology for Modeling and Analysis of Business Processes (MMABP) is founded on several fundamental rules that ensure clarity, consistency, and alignment with the principles of business process modeling:

• Single starting point
• Defined end state
• Incorporation of process states
• Granularity based on external influences
• Activities tied to events
• Flat structure over hierarchy

These rules ensure that business processes are modeled in a way that aligns with the principles of process-driven management, fostering a clear and consistent representation of workflows and interactions within an organization.

Illustrative example (oversimplified)

To illustrate the MMABP methodology and its four components (Process Map, Process Flow Model, Model of Concepts, and Object Life Cycle Model), we will use a simple business scenario of employee management in a company. This example demonstrates how employees are registered, their details updated, and their employment terminated.

Process map

The global process map outlines the key processes within the system

The global process map outlines the key processes within the system:

• Register a new employee
• Update employee details
• Terminate employment

This map serves as a foundation for designing more detailed process models.

Process map rules

• Each process (e.g., "Employee registering etc..) has a distinct triggering event (e.g., "Employee hired," etc..) and a clear target state such as "Employee registered,".
• The processes are named based on the actions leading to their target states, such as "Employee registering".
• Each process belongs to only one business function and business functions are distinct and non-overlapping.
• Events are described as significant changes in the process environment (object states, conditions, or time).

Process flow model

From the global process map, we select one specific process (Employee registering) and represent it using a BPMN diagram. This diagram breaks down the process into individual tasks, such as filling in the employee’s details, verifying them, and creating account into the system. It visually demonstrates the flow of activities required to complete the registration process.

Process diagram of simplified process (Employee registering)

The process flow diagram provides a detailed view of the business processes outlined in the global process map, aiming to ensure consistency between the process map, class diagram, detailed process steps, and object states.

It represents a series of activities designed to deliver the value that the process is intended to achieve.

Process flow model rules

The process flow model begins with an event, followed by a task or activity that is performed. The completion of this activity results in a new state. In this state, the system waits for the next event to trigger further progress. This sequence repeats until the process reaches its end.

Model of concepts

Class diagram of simplified example (Employee management)

The class diagram models the structure of the system in terms of its core concepts. In this case, we represent a "User" class and its specialized subclass "Employee". The "Employee" inherits general attributes and methods from the "User" class, while adding its own specific properties and behaviors. This diagram helps clarify the relationships between the main entities in the system and their respective roles.

The class diagram represents a static view of the real world, illustrating the interconnections between individual business objects within the system.

Object life cycle model

The object life cycle model captures the lifecycle of an individual "Employee" object. It illustrates the states the object transitions through, starting with its creation during registration, moving to its registered state, and potentially being updated before reaching its terminated state. This model does not reflect real-world behavior but instead serves as a detailed ontological representation to ensure the system’s consistency and correctness.

State diagram of simplified object (Employee)

The object life cycle should encompass the entire existence of an object, from its creation to its termination. It begins with an event that triggers its creation and includes all possible termination scenarios. Each state must have at least two outgoing transitions unless it is a final state. This ensures that each state can respond to different events in the process. Without this, the object's state would continue regardless of the events, making process outcomes irrelevant.

The life cycle must be consistent with the process map, meaning it should include the terminal states of processes. It must also align with the class diagram, describing methods in the class diagram that facilitate transitions between states. Additionally, it should correspond with the process diagram, which describes activities and states where the system waits for an event.

The transitions between states describe the reason for moving from one state to another, with the action that causes the state change indicated after a slash.

While this example focuses on the registration process and the corresponding diagrams, a complete model would also include detailed representations for the processes of updating employee details and terminating employment. These additional models would ensure comprehensive coverage of the entire business system.

Contextualizing object life cycle

Object-oriented modeling

Object-oriented modeling (OOM) is a systematic approach to representing applications, systems, and business domains by applying the object-oriented paradigm throughout the development life cycle. It is frequently used for understanding problems, facilitating communication with domain experts, modeling business processes, preparing documentation, and designing programs and databases. At its core, the object-oriented approach organizes software as a collection of objects, each encapsulating both data structures and behaviors. The foundational characteristics of this approach include identity, classification, polymorphism, and inheritance, which collectively enable OOM to create modular, reusable, and scalable software systems.

Object life cycle diagram in OOM

The object life cycle diagram (OLCD) in object-oriented modeling is a key tool for capturing how an object's state evolves throughout its existence. It bridges the static structure of objects (defined in class diagrams) with their dynamic behavior (captured in state diagrams). By defining states, events, and transitions, the OLCD ensures consistency across all phases of the software development life cycle (SDLC).

In object-oriented methodology, objects are central. They can persist throughout SDLC stages maintaining their attributes and behaviors. While many objects reflect real-world entities, some are introduced during design or implementation to optimize performance, such as data structures or algorithms.

The OLCD aligns with three complementary object-oriented models:

• Object Model: Describes the static structure of objects and their relationships.
• Dynamic Model: Captures changes in object states and their transitions.
• Functional Model: Explains data flows and transformations.

The OLCD focuses on the dynamic model, using state diagrams to illustrate transitions between states, triggered by events or actions. This provides a holistic understanding of how objects interact with processes, ensuring alignment with the system's goals and behaviors.

Methodology for modeling and analysis of business processes (MMABP)

The Methodology for Modeling and Analysis of Business Processes (MMABP) is a structured approach designed to address gaps in traditional business process modeling methods like BPMN. It emphasizes aligning business processes with organizational goals and ensuring coherence across various layers of enterprise systems. MMABP was developed using the design science method, focusing on identifying deficiencies in existing methodologies and proposing practical solutions validated through real world projects.

Core principles

The Methodology for Modeling and Analysis of Business Processes (MMABP) is founded on three essential principles:

Principle of modeling

The methodology emphasizes that every business system is a model of the real world. Processes, objects, and interactions are grounded in real world phenomena, ensuring a realistic and practical representation of organizational behavior.

The object model focuses on the fundamental building blocks of reality, such as objects, their attributes, and their relationships. It provides a static view of reality.

• Class diagrams: Used to represent the structure of objects, their attributes, and associations. This diagram defines the static relationships between objects in the system.
• Object life cycle: Captured using state diagram (state machine charts), the object model includes the states an object can assume throughout its lifecycle. This emphasizes transitions triggered by events or actions, reflecting the logical flow of an object's behavior over time.

The process model reflects the dynamic dimension of reality, describing the sequence and logic of actions leading from the initiation of a process to its completion.

• Process diagrams: These capture the behavior of the system and show how processes are executed to achieve specific goals. Each step in a process must correspond to some action or event influencing an object.
• Unlike the object model, the process model is goal-oriented, showing how actions progress toward defined end states.

Principle of three architectures

MMABP defines a hierarchical approach to abstraction through three levels of architecture:

• Conceptual level: Provides a clear and technology independent model of the real world.
• Technological/Organizational level: Focuses on generic aspects of system implementation, such as technologies and organizational structures.
• Physical level: Details specific implementations, including individual skills, tools, and systems.

Principle of abstraction

Abstraction is used to manage complexity, focusing on hierarchical abstractions that help isolate high-level system structures while ensuring detailed elements are addressed as needed.

Object Life Cycle in MMABP

The Methodology for Modeling and Analysis of Business Processes (MMABP) incorporates the concept of an object life cycle as a critical component for understanding and modeling business systems. The object life cycle represents the temporal behavior of individual objects, focusing on the states they assume, transitions they undergo, and events that drive these changes. This detailed view is essential for aligning the static structure of objects with the dynamic behavior of processes.

Core concept of object life cycle in MMABP

The object life cycle in MMABP is modeled using the UML state machine diagram and is complementary to the process model, providing a detailed ontological perspective to the intentionality captured by process flows. It ensures that every action or event within a process is grounded in the context of the object's states.

Each state of an object corresponds to a point within a process. For instance, the state "Approved" in an object lifecycle might align with a decision gate in a process flow. Processes must respect the causality defined in the object lifecycle. For example, an order cannot be shipped unless its state transitions to "Ready for Shipment." Events triggering state transitions also act as synchronization points between objects and processes.

By modeling object life cycles, MMABP bridges the gap between static object structure and dynamic process flow, creating a comprehensive and consistent representation of business systems. This approach ensures that every aspect of the business is captured, from high-level organizational goals to the granular behavior of individual objects.