The Engineering Design of Systems: Models and Methods 3rd Edition Chapter 3 – Modeling and Process Modeling By Dennis Buede and Bill Miller Innovative Decisions, Inc. dbuede@innovativedecisions.com wmiller@innovativedecisions.com Chapter 3 - Modeling and Process Modeling

Chapter 3 - Modeling and Process Modeling Models Incomplete representation of reality Answers questions Types of questions Definitional Descriptive, predictive Normative Chapter 3 - Modeling and Process Modeling

Taxonomy of Models Model Categories Model Subcategories Typical Systems Engineering Questions Physical Full-scale mock-up Subscale mock-up Breadboard How much? How often? How good? Do they match? Quantitative Analytic Simulation Judgmental Qualitative Symbolic Textual Graphic What needs to be done? How well? By what? Mental Explanation All of the above! Chapter 3 - Modeling and Process Modeling

Chapter 3 - Modeling and Process Modeling Modeling Languages Semantics: signs and symbols Syntax: way in which signs and symbols are put together Chapter 3 - Modeling and Process Modeling

Chapter 3 - Modeling and Process Modeling SysML Modeling meta-system modeling with use case and associated sequence diagrams as well as requirements relations with requirements diagram, behavior modeling of the system’s activities or processes (including both static and dynamic modeling) using activity and state machine diagrams, structural modeling of the system’s components including block definition and internal block diagrams, parametric modeling of performance characteristics of the system. the process and structure of that the systems engineering team is taking using package diagrams. Chapter 3 - Modeling and Process Modeling

Comparison of SysML to Traditional SE Modeling Techniques Chapter 3 - Modeling and Process Modeling

Chapter 3 - Modeling and Process Modeling Use Case Diagram Chapter 3 - Modeling and Process Modeling

Chapter 3 - Modeling and Process Modeling Sequence Diagram Chapter 3 - Modeling and Process Modeling

Chapter 3 - Modeling and Process Modeling IDEF0 Genesis: Air Force’s Integrated Computer-Aided Manufacturing (ICAM) program Variation of Structured Analysis & Design Technique (SADT), SofTech - David Ross ICAM Definition originally Integrated Definition 0 in 2012 Chapter 3 - Modeling and Process Modeling

IDEF0 Semantics & Syntax Model Semantics: Collection of pages Syntax: Hierarchical structure Page Semantics: Boxes and arrows Boxes: Functions, processes, activities Arrows: Flow of material or data Inputs enter from left Controls enter from top Outputs leave from right Mechanisms enter from bottom Syntax: Interaction of functions via material & data Transforms inputs into outputs Using guidance of controls As performed by mechanisms Chapter 3 - Modeling and Process Modeling

Chapter 3 - Modeling and Process Modeling IDEF0 Model Answers definitive questions about the transformation of inputs into outputs by the system Establishes the boundary of the system on the context page. This boundary is explicated, if needed, as a meta description. Has one viewpoint; the viewpoint is the vantage or perspective from which the system is observed. Is a coordinated set of diagrams, using both a graphical language and natural language. Chapter 3 - Modeling and Process Modeling

IDEF0 Rules & Guidelines Conservation of inputs, controls, outputs & mechanisms Every function has a control and output Guidelines 3 to 6 functions per page arranged diagonally Control-oriented functions placed at top left Major output functions placed on bottom right Arcs & functions are decomposable Feedback is defined by arcs moving from bottom right to top left Chapter 3 - Modeling and Process Modeling

Chapter 3 - Modeling and Process Modeling Arrow Semantics Chapter 3 - Modeling and Process Modeling

Feedback Semantics of Functions Chapter 3 - Modeling and Process Modeling

IDEF0 Page Structure Chapter 3 - Modeling and Process Modeling Page Number(s) Page Content A - 1 Ancestor or external system diagram A - 0 Context or system function diagram (contains A0) A0 Level 0 diagram with first tier functions specified A1, A2, ... Level 1 diagrams with second tier functions specified A11, A12, ..., A21, ... Level 2 diagrams with third tier functions specified ... … Chapter 3 - Modeling and Process Modeling

IDEF0 Functional Decomposition Chapter 3 - Modeling and Process Modeling

Function Flow Block Diagrams Basic Series Concurrent Selection Multiple-exit function Enhanced Iteration Looping Replication Series Concurrent Chapter 3 - Modeling and Process Modeling

Selection & Multiple-exit Functions, Iteration, Looping in FFBD Chapter 3 - Modeling and Process Modeling

Chapter 3 - Modeling and Process Modeling Selection, multiple-exit functions and inputs/outputs between functions in an EFFBD Chapter 3 - Modeling and Process Modeling

Chapter 3 - Modeling and Process Modeling Selection, multiple-exit activities and inputs/outputs between activities in an activity diagram Chapter 3 - Modeling and Process Modeling

Semantic Elements of a Block Definition Diagram Chapter 3 - Modeling and Process Modeling

Block Definition Diagram Chapter 3 - Modeling and Process Modeling

Semantic Elements of Internal Block Diagram Chapter 3 - Modeling and Process Modeling

Internal Block Diagram Chapter 3 - Modeling and Process Modeling

Chapter 3 - Modeling and Process Modeling Semantic elements for the block definition diagram used for performance modeling Chapter 3 - Modeling and Process Modeling

Block Diagram for Fundamental Objectives Chapter 3 - Modeling and Process Modeling