Database Structure

Modeling in Sigmafine is presented in the following series of functional parts:

• Models
• Element Templates
• Elements
• Connections
• Layers
• Analyses

Models

Models contain collections of elements and their connectivity (how they are connected to one another). They contain the definition of layers for Element organization. They also contain a collection of analyses that can be done on that model. See PI AF Builder for additional information.

Element Templates

Elements in Sigmafine Models are based on Element templates that configure all the necessary Attributes of the element. Templates can be for very broad, or very specific use. For example, a template can define a specific type of measurement device or a specific type of equipment. The Element templates that are pre-configured with the Sigmafine installation are broad-use templates.

For example: The Sigmafine Element template SF_ReceiptPoint is a general template for any material entering a facility. Instances of this template could include these objects.

• Dock A, Dock B, Dock C
• Truck Scale 1
• Pipeline XYZ
• Railcar

Element templates also specify the ports for an element. Ports are the locations where an Element connects to the model. Ports also define a flow direction which then determines inputs and outputs from the element.

Elements

In a Sigmafine model, elements are based on Element templates. An Element is an item within the Sigmafine Model that represents a physical device, piece of equipment, storage container, or representative section of a process. Sigmafine has the following types of elements.

• Boundaries
• Flows
• Measurements
• Nodes
• Transfers

The main distinction between the types is their use of ports, which are the connection points of an element. These are the three types of ports:

• Input – These ports receive material from the upstream process.
• Output – These ports send material to the downstream process.
• Undirected – These ports are usually used for attaching measurements on the material within the element.

Details on how Sigmafine uses these Element types are given below.

Element Type	Description
Boundaries	Use boundary elements to set the limits of a model. These provide initial sources and ultimate destinations of the model. The Attributes of boundary elements specify the ports for the model. Sigmafine uses the boundary Element to define receipt and shipment point elements. These transfer points define the "fence line" of a facility. SF_RecepitPointTemplate and SF_ShipmentPointTemplate are examples of Boundaries.
Flows	Flow elements carry material from one Element to another. Sigmafine uses flows for: pipes, conveyers, heat exchangers and other components that only have a single input and a single output. Flows typically have measurement elements that attach to the undirected port for the flow. SF_FlowTemplate is an example of Flows.
Measurements	Measurement elements represent a measurement device, or a measurement derived from calculation. These measurements are attached to flow and node elements through their one undirected port. Sigmafine uses measurement elements to represent meters and analyzers in the model. SF_AnalyzerTemplate, SF_GasMeterTemplate, SF_LiquidMeterTemplate and SF_SolidMeterTemplate are examples of Measurements.
Nodes	Node elements represent physical equipment in the Model or areas of equipment. Nodes have input and output ports and in the Case of nodes that are representing tanks, they also have undirected ports for attaching level measurements, temperature measurements, etc. SF_NodeTemplate, SF_ProcessTemplate, SF_GaugedTankTemplate and SF_VolumeTankTemplate are examples of Nodes.
Transfers	Transfer elements mark movement of material in discreet quantities. Transfer elements are unique in a Model because they are temporal. The transfer has a start time and an end time, and the elements only appear in a Model when a transfer has taken place. Sigmafine uses transfers to track material movements in and out of the facility, track raw materials used in the process and finished product being stored, and track tank-to-tank material transfers. SF_TransferTemplate is an example of Transfers
Element Attributes	The term "attribute" is used for the characteristics of an Element template and the elements that are based on the template. These Attributes are defined at the Element template configuration. Attributes can be assigned a Unit of Measure. This Unit of Measure is then tracked and can convert between different engineering units. For example, a liquid flow meter Element template could include the following attributes.Flow rate, with units of cubic meters per hour.Temperature with units of degrees C.Density with units of kilograms per cubic meter.Attributes also allow elements to reference Sigmafine calculations and outside data through the configuration of a "data reference." Data references are plug-ins and allow data to derive from automated field data collection and business systems, formula calculations and Sigmafine calculations.For example: In a flow element, the material Attribute might reference material information populated from an inventory table listing and the process Attributes of temperature, flow rate, and density populated from tags on the PI Server. In this Case the material Attribute uses a data reference called the Table Lookup Data Reference and those referencing the PI server use the PI Point Data Reference.

Connections

Elements in a Model are connected through any number of ports, which are defined by the Element template. A port can be defined as an input port, an output port, or as an undirected port. The port also defines how many connections can exist and the types of elements that can be connected.

In Sigmafine analyses, directed ports (input and output ports) represent positive material flow and are used by connections. Undirected ports are used by attachments of meters and analyzers. The most common type of attachment in a Sigmafine Model is a measurement or meter attached to a flow element.

Layers

You can organize the elements of a Model into layers. Layers provide a mechanism for including or excluding portions of the Model as needed for analysis. An Element of a Model can belong to more than one layer.

Analyses

After a Model is configured, analysis on the Model is performed using the Sigmafine Analysis Rules. These analysis rules allow for different calculations to be done on a model. Most analysis rules need to have a specified timed interval over which the analysis is run. This period is known as a time rule.

When an analysis over a specified period is performed, the results are stored together in a case. Results in the Case vary depending on the analysis. A mass balance analysis will have Case results with the reconciled value set as well as other metrics.