Integrated Definition (IDEF) Modeling Techniques Ozgun Demirag Andy Johnson Dima Nazzal Yen-Tai Wan
Outline • What is IDEF? • IDEF Family: • Overview • Examples • Strengths and Weaknesses • Rasmussen - Design Maps Definition
What is IDEF? • Definition: IDEF is the common name referring to classes of enterprise modeling languages. • Objective: IDEF is used for modeling activities necessary to support system analysis, design, improvement or integration. Originally, IDEF was developed to enhance communication among people trying to understand the system. Now, IDEF is being used for documentation, understanding, design, analysis, planning, and Integration.
IDEF History • In the 1970’s, IDEF0 originated in the U.S. Air Force under the Integrated Computer Aided Manufacturing(ICAM) program from a well-established graphical language, the Structured Analysis and Design Technique (SADT).
IDEF Family • IDEF Family of Methods: • IDEF0: for Function Modeling (purpose:description) • IDEF1: for Information Modeling.(purpose:description) • IDEF1x: for Data Modeling. (purpose:design) • IDEF3: for Process Modeling. (purpose:description) • IDEF4: for Object-Oriented Design.(purpose:design) • IDEF5: for Ontology Description Capture. (purpose:description)
IDEF0- Function Modeling Method • IDEF0 models the decisions, actions, and activities of an organization or system, in order to communicate the functional perspective of a system. • IDEF0 models are created as one of the first tasks of a system development effort because they describe: • the functions that are performed, • what is needed to perform those functions, • IDEF0 was released as a standard for Function Modeling by the Computer Systems Laboratory of the National Institute of Standards and Technology. (1993)
Controls Function Name Outputs Inputs Mechanisms IDEF0- Function Modeling Method • Syntax: • Context Diagram: is a model of the function at the highest level of inputs, controls, outputs, and mechanisms • Inputs: items that trigger the activity • Controls: guide or regulate the activity • Mechanisms: systems, people, equipment used to perform the activity • Outputs: results of performing the activity
IDEF0- Function Modeling Method • Decomposition Diagram: links together the context diagrams
IDEF0- Function Modeling Method • STRENGTHS • The model has proven effective in detailing the system activities for function modeling. • IDEF0 models provide an abstraction away from timing, sequencing and decision logic. However, it is easy to use IDEF0 for modeling activity sequences whenever needed. (Order the activities from left to right in the decomposition diagram). • Provides a concise description of systems, by using the ICOMS. (Inputs, Controls, Output, Mechanism) • The hierarchical nature of IDEF0 allows the system to be easily refined into greater detail until the model is as descriptive as necessary for the decision making task.
IDEF0- Function Modeling Method • WEAKNESSES • IDEF models might be so concise that only the domain experts can understand. • IDEF models are sometimes misinterpreted as representing a sequence of activities. • The abstraction away from timing, sequencing and decision logic leads to comprehension difficulties for the people outside the domain.
IDEF0- Function Modeling Method • EXAMPLE (source: )
IDEF1- Information Modeling Method • IDEF1 is a method for both analyzing and communicating the structure and semantics of information within a system. • IDEF1 models are used to: • Identify what information is currently managed in a real-world system, both automated system components, and non-automated objects (e.g. people). • Identify the rules for managing the information. • Identify deficiencies in the current management of the information. • Specify what information will be managed in a TO-BE implementation.(TO-BE implementation: Design of the functional architecture)
IDEF1- Information Modeling Method • Main IDEF1 Concepts • Entities: Represent the information maintained in a system about the real-world objects • Distinguishing properties: • Persistent • May be individuated • Attributes: • Key • Non-key • Relations: Association between entities
IDEF1- Information Modeling Method • STRENGTHS • IDEF1 requires active participation of the information users, which serves to accurately model where and how the information is used and managed. • An effective method for documenting the informational requirements of an enterprise, providing a foundation for database design. • IDEF1 enforces a modularity that eliminates the incompleteness, imprecision, inconsistencies, and inaccuracies found in the modeling process.
IDEF1x- Data Modeling Method • IDEF1X is a method for designing relational databases. • IDEF1X Model: Graphical and Textual depiction of “What must I know to do what I do?” • IDEF1X is most useful for logical database design after the information requirements are known and the decision to implement a relational database has been made. • IDEF1X was released as a standard for Data Modeling by the Computer Systems Laboratory of the National Institute of Standards and Technology. (1993)
IDEF1x- Data Modeling Method • EXAMPLE (ref:)
IDEF1x- Data Modeling Method • EXAMPLE (ref:)
IDEF1x- Data Modeling Method • STRENGTHS • Powerful tool for data modeling. • IDEF1X don’t have numerous variants, unlike ER. • Depicts the rules governing the management of information. • Used to validate the concepts in the associated IDEF0 model. • Helps to discover underlying causes for problems. • WEAKNESSES • The modeler must be experienced in order to create good models. • Not suited to serve as an AS-IS analysis tool.
IDEF3- Process Description Model • “IDEF3 is a mechanism for collecting and documenting processes.… IDEF3 captures the behavioral aspects of an existing or proposed system.” (temporal information, including precedence and causality relationships associated with enterprise processes.) • “The resulting IDEF3 descriptions provide a structured knowledge base for constructing analytical and design models. (unlike simulation languages that build predictive mathematical models, IDEF3 builds structured descriptions.)” • “These descriptions capture information about what a system actually does or will do and also provide for the organization and expression of different user views of the system.” Sounds Familiar ! Source: http://www.idef.com/idef3.html
Process Description Diagram Object State Transition Network IDEF3- Process Description Model • The development of an IDEF3 Process Flow Description consists of expressing facts, collected from domain experts, in terms of five basic descriptive building blocks. • Activity Denoted as arcs • Logic Denoted as junction boxes • Unit of Behavior Denoted as boxes • Object State Denoted as circles • State Transition Denoted as arcs Source: http://www.idef.com/idef3.html
IDEF3- Process Description Model • Organizing Structure: Scenario A scenario can be thought of as a recurring situation, a set of situations that describe a typical class of problems addressed by an organization or system, or the setting within which a process occurs. • Example Scenario: Parts enter the shop ready for the primer coat to be applied. We apply one very heavy coat of primer paint at a very high temperature. The paint is allowed to dry in a bake oven after which a paint coverage test is performed on the part. If the test reveals that not enough primer paint has been sprayed on the surface of the part, the part is re-routed through the paint shop again. If the part passes the inspection, it is routed to the next stop in the process. Source: http://www.idef.com/idef3.html
IDEF3- Process Description Model • Process Description Diagram of the Example Source: http://www.idef.com/idef3.html
IDEF3- Process Description Model • Object State Transition Network of the Example Source: http://www.idef.com/idef3.html
IDEF3- Process Description Model • Other Example Source: (Zakarian & Kusiak, 2001)
IDEF3- Process Description Model • Other Example Source: (Bosilj-Vuksic’s , 2000)
Schema Process Is IDEF3 a good way to represent process reference models ? Reference Model Domain Model Instance IDEF3- Process Description Model • Discussion • The statement of IDEF3 sounds like … Source: http://www.isye.gatech.edu/~lfm/8851/ISyE8851.html
IDEF4- O-O Design Method • IDEF4 method is designed to assist in creating object-oriented programming software. • IDEF4 provides a framework for navigating an evolving object-oriented design. • IDEF4 divides the object-oriented design activity into discrete chunks. A graphical syntax highlights the design decisions that must be made and their impact on other perspectives of the design. • IDEF4 model consists of two submodels, the class submodel and the method submodel. These two structures capture all the information represented in a design model.
IDEF5 - Ontology Description Method • An ontology is a domain vocabulary complete with a set of precise definitions or axioms that constrain the meanings of the terms sufficiently, to enable consistent interpretation of the data that use that vocabulary. • General ontology construction steps: 1. catalog the terms; 2. capture the constraints that govern how those terms can be used to make descriptive statements about the domain; and 3. build the model.
IDEF5 - Ontology Description Method The IDEF5 ontology development process consists of the following activities. • Data Collection of raw data needed for ontology development. • Data Analysis to facilitate ontology extraction. • Initial Ontology Development to develop a preliminary ontology from the data gathered. • Ontology Refinement and Validation.
REALITY NARRATIVEMODEL INTERVENE OBSERVE SYMBOLICMODEL PLANNINGMODEL COMPUTATIONALMODEL NORMATIVEMODEL SYNTHETICMODEL The “modeling cycle” I DEF
Rasmussen - Design Maps Definition • Map 1: Domain, tasks, and user in context • Map 2: Knowledge base • Map 3: Road maps for navigation • Map 4: Knowledge representation in design • Map 5: Display composition
Map 1: Domain, tasks, and user in context Map 2: Knowledge base Map 3: Road maps for navigation Map 4: Knowledge representation in design Map 5: Display composition IDEF0 (IDEF Function Modeling) IDEF1 (IDEF Information Modeling) IDEF1X (IDEF Data Modeling) IDEF3 (IDEF Process Modeling) IDEF4 (IDEF Object-Oriented Design) IDEF5 (IDEF Ontology Description Capture) Side by Side Comparison
Rasmussen Map 1 compared to IDEF0- Diagram • Decomposition Diagram: links together the context diagrams
Key • Both require an expert in the field to use and understand the model • This is a result of the method being a very high level concept and developing the details for any single application is not a trivial matter
Advantage of IDEF • IDEF 5 attempts to incorporate the vocabulary of the specific application
References • Colquhoun, G.J, Baines, R.W, Crossley, Roger, A State of the Art Review of IDEF0, International Journal of Computer Integrated Manufacturing, Vol. 6, No. 4, 1993, pp. 252-264. • (2) Introduction to IDEF Methodology, USACE LCM Manager’s Guide Version-2 http://www.usace.army.mil/ci/impolicy/lcmis/lcma3.pdf • (4) Bosilj-Vuksic’s paper (http://oliver.efzg.hr/~vbosilj/iceis2000.pdf)