Control flow diagram
Encyclopedia
A control flow diagram is a diagram
Diagram
A diagram is a two-dimensional geometric symbolic representation of information according to some visualization technique. Sometimes, the technique uses a three-dimensional visualization which is then projected onto the two-dimensional surface...

 to describe the control flow
Control flow
In computer science, control flow refers to the order in which the individual statements, instructions, or function calls of an imperative or a declarative program are executed or evaluated....

 of a business process
Business process
A business process or business method is a collection of related, structured activities or tasks that produce a specific service or product for a particular customer or customers...

, process
Process (engineering)
In engineering a process is a set of interrelated tasks that, together, transform inputs into outputs. These tasks may be carried out by people, nature, or machines using resources; so an engineering process must be considered in the context of the agents carrying out the tasks, and the resource...

 or program.

Control flow diagrams were developed in the 1950s, and are widely used in multiple engineering
Engineering
Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

 disciplines. They are one of the classic business process modeling
Business process modeling
Business Process Modeling in systems engineering is the activity of representing processes of an enterprise, so that the current process may be analyzed and improved. BPM is typically performed by business analysts and managers who are seeking to improve process efficiency and quality...

 methodologies, along with flow charts, data flow diagram
Data flow diagram
A data flow diagram is a graphical representation of the "flow" of data through an information system, modelling its process aspects. Often they are a preliminary step used to create an overview of the system which can later be elaborated...

s, functional flow block diagram
Functional flow block diagram
A Functional Flow Block Diagram is a multi-tier, time-sequenced, step-by-step flow diagram of a system’s functional flow.The FFBD notation was developed in the 1950s, and is widely used in classical systems engineering...

, Gantt chart
Gantt chart
A Gantt chart is a type of bar chart that illustrates a project schedule. Gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project. Terminal elements and summary elements comprise the work breakdown structure of the project. Some Gantt charts...

s, PERT diagrams, and IDEF
IDEF
IDEF, an abbreviation of Integration Definition, refers to a family of modeling languages in the field of systems and software engineering. They cover a wide range of uses, from functional modeling to data, simulation, object-oriented analysis/design and knowledge acquisition. These "definition...

.

Overview

A control flow diagram can consist of a subdivision to show sequential steps, with if-then-else conditions, repetition, and/or case conditions. Suitably annotated geometrical figures are used to represent operations, data, or equipment, and arrows are used to indicate the sequential flow from one to another.

There are several types of control flow diagrams, for example:
  • Change control flow diagram, used in project management
    Project management
    Project management is the discipline of planning, organizing, securing, and managing resources to achieve specific goals. A project is a temporary endeavor with a defined beginning and end , undertaken to meet unique goals and objectives, typically to bring about beneficial change or added value...

  • Configuration decision control flow diagram, used in configuration management
    Configuration management
    Configuration management is a field of management that focuses on establishing and maintaining consistency of a system or product's performance and its functional and physical attributes with its requirements, design, and operational information throughout its life.For information assurance, CM...

  • Process control flow diagram, used in process management
    Process management
    Process management is the ensemble of activities of planning and monitoring the performance of a process. The term usually refers to the management of business processes and manufacturing processes...

  • Quality control flow diagram, used in quality control
    Quality control
    Quality control, or QC for short, is a process by which entities review the quality of all factors involved in production. This approach places an emphasis on three aspects:...

    .


In software and systems development control flow diagrams can be used in control flow analysis
Control flow analysis
Control flow analysis is a static code analysis technique for determining the control flow of a program. The control flow is expressed as a control flow graph .For many languages, the control flow of a program is explicit in a program's source code...

, data flow analysis, algorithm analysis, and simulation
Simulation
Simulation is the imitation of some real thing available, state of affairs, or process. The act of simulating something generally entails representing certain key characteristics or behaviours of a selected physical or abstract system....

. Control and data flow analysis are most applicable for real time and data driven systems. These flow analyses transform logic and data requirements text into graphic flows which are easier to analyze than the text. PERT, state transition, and transaction diagrams are examples of control flow diagrams.

Process Control Flow Diagram

A flow diagram can be developed for the process control system
Control system
A control system is a device, or set of devices to manage, command, direct or regulate the behavior of other devices or system.There are two common classes of control systems, with many variations and combinations: logic or sequential controls, and feedback or linear controls...

 for each critical activity. Process control is normally a closed cycle in which a sensor
Sensor
A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. For example, a mercury-in-glass thermometer converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated...

 provides information to a process control software application through a communications system
Communications system
In telecommunication, a communications system is a collection of individual communications networks, transmission systems, relay stations, tributary stations, and data terminal equipment usually capable of interconnection and interoperation to form an integrated whole...

. The application determines if the sensor information is within the predetermined (or calculated) data parameters and constraints. The results of this comparison are fed to an actuator, which controls the critical component. This feedback
Feedback
Feedback describes the situation when output from an event or phenomenon in the past will influence an occurrence or occurrences of the same Feedback describes the situation when output from (or information about the result of) an event or phenomenon in the past will influence an occurrence or...

 may control the component electronically or may indicate the need for a manual action.

This closed-cycle process has many checks and balances to ensure that it stays safe. The investigation of how the process control can be subverted is likely to be extensive because all or part of the process control may be
oral instructions to an individual monitoring the process. It may be fully computer controlled and automated, or it may be a hybrid in which only the sensor is automated and the action requires manual intervention. Further, some process control systems may use prior generations of hardware and software, while others are state of the art.

Performance seeking control flow diagram

The figure presents an example of a performance seeking control flow diagram
Flow diagram
Flow diagram may refer to:* Alluvial diagram, highlights and summarizes the significant structural changes in networks* Flowchart, schematic representation of a process which can give a step-by-step solution to a given problem....

 of the algorithm. The control law consists of estimation, modeling, and optimization processes. In the Kalman filter
Kalman filter
In statistics, the Kalman filter is a mathematical method named after Rudolf E. Kálmán. Its purpose is to use measurements observed over time, containing noise and other inaccuracies, and produce values that tend to be closer to the true values of the measurements and their associated calculated...

estimator, the inputs, outputs, and residuals were recorded. At the compact propulsion system modeling stage, all the estimated inlet and engine parameters were recorded.

In addition to temperatures, pressures, and control positions, such estimated parameters as stall margins, thrust, and drag components were recorded. In the optimization phase, the operating condition constraints, optimal solution, and linear programming health status condition codes were recorded. Finally, the actual commands that were sent to the engine through the DEEC were recorded.
dfd(data float diagam)is network manen ment system that is good.
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