POSC Specifications
Version 2.2		 Epicentre Logical Data Model
Topic Discussions

Equipment and Facilities (EQ)

Introduction

The equipment and facilities model (EQ) defines structures and re-usable concepts for equipment and facility data.

The concept of Equipment corresponds to manufactured, non consumable materials. Specific things that have an intentional shape and form and have mass. An example of equipment is an actual pump with serial number 1234.

In contrast, a Facility is a business function or service. Facilities are concepts we use to run a business. Equipment and materials may be installed to provide the function or service. Facilities enable business function to be described independently of the equipment or materials that may be installed from time to time. Examples of facility are Pump Station 1 in a product distribution facility and Manifold 24 of a gathering system.

Equipment may be installed for a facility, meaning that the equipment is appropriately positioned and connected to any other necessary equipment to provide the service defined by the facility (Figure 1).

Equipment and Facility specify the concepts of object and service

The concept of facility is widely used within the E&P business where actual or expected performance of particular functions is the norm. Operation of equipment is frequently described in terms of facilities and not equipment. For example, operational instructions typically refer to the facility Valve A and not to the equipment Valve serial number 3108956.

Eight ER diagrams describe equipment and facilities:

What's New in v2.2?

Equipment

The concepts of Equipment_item, Catalog_equipment and Equipment_class are covered in the topic, Equipment. Catalog_equipment corresponds to the concept of a reusable design that defines some intended characteristics of equipment items that may be manufactured or produced in accordance with that design. As the name implies, Catalog_equipment is a thing you might find in a manufacturer's catalog, with a part number and specification - if you order one of these, the actual thing that arrives is the Equipment_item.

Equipment_items have mass and consist of non consumable material. They are often manufactured or constructed in accordance with a design but each may have specific characteristics that differ from the design intentions. For example an electrical resistor manufactured to have a resistance of 15 ohm may have a resistance which is 15.3 ohm.

Equipment_class defines criteria for classifying Equipment_item and Catalog_equipment. The key concept is that a class defines a range of characteristics and members fit within the range. This is separate from the concept of a design where some point values of the resulting product are intended. The interaction of these three concepts is illustrated in Figure 2.

Item / Class / Catalog

Equipment Item

Equipment_item corresponds to specific manufactured or man made non consumable materials. Equipment_items have mass and shape. Equipment_item is a subclass of Inventory_object and inherits an optional identifier and an optional set of inventory_object_aliases.

Equipment_items must have a  ref_existence_kind which is one of the existence qualifiers of actual, planned, required or predicted. The meanings of these terms in the context of equipment are as follows:

Examples of Equipment_items:
 
Equipment Item 
SUIa  Identifier  Ref existence kind  Description 
#EQ1  27458  Actual  Anvil centrifugal pump type 23 
#EQ2  87269  Actual  Electric motor 47 hp 
#EQ3  DC6891  Actual  Impeller 20 gpm at 200 rpm 
#EQ4  -  Planned  Impeller 32 gpm at 120 rpm 
#EQ5  64953  Actual  Anvil type 23 Pump parts kit 
#EQ6  19752  Actual  Impeller 32 gpm at 120 rpm 
#EQ7  BP7592  Actual  Better Pump Co. model DZ200 
 
Note the difference between planned and actual Equipment_items. #EQ4 represents a new impeller on order from the manufacturer and so is a planned equipment item. While on order it is not given an identifier. When the order is fulfilled an actual equipment item instance #EQ6 is created to represent the actual impeller.

Equipment_composition associates an Equipment_item or a Catalog_equipment as a part of a whole Equipment_item. The association is valid for a period of time. Equipment_item may be a part of several other equipment items either sequentially or simultaneously. Equipment_composition must be one of two types; either an assembly or a collection.

Equipment_item_assembly describes a structure where the parts are dependent or related to other parts of the assembly. An example use of this entity is shown below to describe the assembled Anvil type 23 pump. Note the 20 gpm impeller is replaced by a new impeller of greater efficiency part way through the life of the pump.
 
Equipment Item Assembly 
SUIa Whole Part Start time End time
#EQ10  #EQ1  #EQ2  7Feb85  - 
#EQ11  #EQ1  #EQ3  7Feb85  19Jan89 
#EQ12  #EQ1  #EQ6  20Jan89  - 
 
Equipment_item_collection describes the parts of a whole equipment item where the parts are unrelated to each other. An example of its use is to describe a kit of parts. This is shown below.
 
Equipment Item Collection
SUIa Whole Part Start time End time
#EQ13  #EQ5  #EQ2  1Feb85  7Feb85 
#EQ14  #EQ5  #EQ3  1Feb85  7Feb85 
#EQ15  #EQ5  #EQ6  5Jan89  20Jan89 
#EQ16  #EQ5  #EQ3  20Jan89  - 
 
Note that #EQ3, the less efficient impeller, has two periods for which it is in the parts kit, prior to pump assembly and returning to the kit when replaced by the more efficient impeller #EQ6. Also #EQ3 is a part of the parts kit and a part of the assembled pump.

Equipment_item may be connected thereby describing the assembly structure. Connections are described by the transient association Equipment_item_connection. The pieces of equipment forming the connection are also Equipment_items. The impeller DC6891 has a drive shaft component which connects to a clutch drive component of the electric motor 87269.
 
Equipment Item
SUIa Identifier Ref existence kind Description
#EQ8  -  Actual  Motor clutch load drive
#EQ9  -  Actual  Impeller drive
 
Equipment Item Assembly
SUIa Whole Part Start time End time
#EQ17  #EQ2  #EQ8  1Feb85  - 
#EQ18  #EQ3  #EQ9  1Feb85  - 
 
Equipment Item Connection
SUIa To Equipment From equipment Start time End time
#EQ21  #EQ8  #EQ9  1Feb85  - 
 
Note, the details of the connection (for example, bolted flange or universal joint) are not described but could be using further decomposition.

Catalog Equipment

Catalog_equipment corresponds to reusable designs of equipment where there is usually one or more specific characteristics of the design.

A familiar example of a Catalog_equipment is a manufacturer's model. This describes or is the design which is used to manufacture many actual Equipment_items. The design specifies intended characteristics for the resulting equipment. In the model, the design characteristics are expressed as properties which are described later in the section for diagram EQW4: Equipment Properties. Examples of Catalog_equipment are given below.
 
Catalog Equipment
SUIa Identifier Description
#CE1  ACP23  Anvil centrifugal pump type 23 
#CE2  EM-047  Faraday Electric motor 47 hp 
#CE3  IMP473  Goings Impeller 20 gpm at 200 rpm 
 
Note that in the example, the identifiers correspond to model numbers used by the manufacturer. The use of multiple identifiers or aliases for equipment is discussed in the section for diagram EQW5: Equipment Inventory.

The above Catalog_equipment are the designs or models of the earlier equipment item examples. For example, the pump with id 27458 is manufactured using the model design ACP23. This can be recorded using the attribute catalog_equipment of Equipment_item as indicated below.
 
Equipment Item (with Catalog Equipment added)
SUIa Identifier Ref existence kind Catalog equipment Description
#EQ1  27458  Actual  #CE1  Anvil centrifugal pump type 23 
#EQ2  87269  Actual  #CE2  Electric motor 47 hp 
#EQ3  DC6891  Actual  #CE3  Impeller 20 gpm at 200 rpm 
 
Catalog_equipment may also be described in terms of its parts where these are other designs or models. In the example, the pump model ACP23 consists of a type of motor EM-047 and an impeller type IMP473. The Catalog_equipment_composition is used to record this information.
 
Catalog Equipment Composition
SUIa Whole Part Start time End time
#CE11  #CE1  #CE2  1Feb81  - 
#CE12  #CE1  #CE3  1Feb81  - 
 
Catalog_equipment designs may be derived from other designs. Catalog_equipment_version enables this information to be held. In the example, a new model of the type 23 pump is introduced with the more efficient 32 gpm impeller. The new model is known by the manufacturer as ACP23/32 and it is derived from ACP23. The example data is represented in the following tables.
 
Catalog Equipment
SUIa Identifier Description
#CE4  ACP23/32  Anvil centrifugal pump type 23 (32 gpm)
#CE5  IMP478  Goings Impeller 32 gpm at 200 rpm 
 
Catalog Equipment Composition
SUIa Whole Part Start time End time
#CE14  #CE4  #CE2  1Feb84  - 
#CE15  #CE4  #CE5  1Feb84  - 
 
Catalog Equipment Version
SUIa Original Version Start time End time
#CE21  #CE1  #CE4  1Feb84  - 
 
The original pump design ACP23 is phased out and replaced by the later design ACP23/32. Catalog_equipment_succession allows this information to be held.
 
Catalog Equipment Succession
SUIa Succeeded Successor Start time End time
#CE31  #CE1  #CE4  1Feb86  - 
 
Note that the form of the model allows a design to be derived from many designs and separates the concepts of version and the status of a version with respect to versions it may replace.

Equipment Class

Equipment_class defines criteria for grouping Equipment_item and Catalog_equipment into classes. The criteria provide a means of accepting or rejecting candidate members.

Equipment_item and Catalog_equipment may have many classifications simultaneously or through time. Equipment_class is distinct from Catalog_equipment in that members of a class have a range of some characteristics, whereas Catalog_equipment are designs that define intended characteristics. Catalog_equipment may also be members of Equipment_class.

Classes may be defined based on usage, tax status, health and safety regulations, some physical property or properties of almost anything. Some examples of Equipment_class that might be relevant to the pump example are shown.
 
Equipment Class
SUIa Name Description
#EC1  Liquid Pump  Mechanical devices for imparting kinetic energy to a liquid. 
#EC2  Centrifugal pump  Liquid pumps that use a continuously rotating impeller. 
#EC3  Electrical pump  Liquid pumps that use an electric motor to provide mechanical energy. 
#EC4  Flame proof  Equipment that is suitable for operation in fire hazard areas. 
#EC5  Electrical equipment  Equipment that utilize electricity. 
 
Equipment Item Classification
SUIa Equipment class Equipment item Start time End time
#EC11  #EC2  #EQ1  -  - 
#EC12  #EC3  #EQ1  -  - 
#EC13  #EC4  #EQ1  -  - 
 
Note that pump 27458 is classified as a centrifugal pump, an electrical pump and as flame proof equipment.

Equipment_classes may themselves be classified as being members of other Equipment_classes. For example electrical pump class may be defined as being in the class of electrical equipment, and electrical pump to be in the class of liquid pump.
 
Equipment Class Classification
SUIa Be classified as Have as a member Start time End time
#EC21  #EC5  #EC3  -  - 
#EC22  #EC1  #EC3  -  - 
 
Equipment_class is also used to classify Catalog_equipment. For example EM-047, Faraday 47 hp Electric Motor may be classified as electrical equipment as follows .
 
Catalog Equipment Classification
SUIa Equipment class Member Start time End time
#EC21  #EC5  #CE2  -  - 

Catalog Equipment Subtypes

Diagram EQW3: Catalog Equipment shows the defined subtypes of Catalog_equipment. The subtypes are preserved from previous versions of Epicentre to provide continuity. Each subtype is intended to have a corresponding Equipment_class reference instance.

Catalog_equipment_material_specification enables the design to specify particular Typical_materials. The example shows a particular type of steel specified for the impeller casing of the IMP473 Goings impeller model.
 
Catalog Equipment
SUIa Identifier Description
#CE6  IMP473-C  Goings Impeller IMP473 casing 
 
Catalog Equipment Composition
SUIa Whole Part Start time End time
#CE16  #CE5  #CE6  1Feb84  - 
 
Catalog Equipment Material Specification
SUIa Catalog equipment Typical material Start time End time
#CE41  #CE6  #TM1  1Feb84  - 
 
Typical Material
SUIa Name Description
#TM1  GNG-5279  Low carbon steel, coef. of expansion = 0.002 per deg C, carbon = 70 ppm 

Equipment Properties

Model diagram EQW4: Equipment Property shows the concepts of property as applied to Equipment_item, Equipment_class and Catalog_equipment.

Pty_equipment_facility associates a property type and a value representation. The property type defines the role of the value representation for the equipment. Five types of representation are defined as subtypes of Pty_equipment_facility, corresponding to different data types:

The property type is recorded as Ref_property_kind, which is constructed from Ref_property_type, Ref_kind_descriptor and Ref_property_qualifier. An example of equipment property is shown for the electric motor 87269.
 
 Pty_quantity (subtype of Pty_equipment_facility)
SUIa Equipment item Start time End time Ref property kind Quantity value
#PY1  EQ2  23Jul85  23Jul85  #PK1  72 Amperes, electric current 
#PY2  EQ2  -  -  #PK2  70 Amperes, electric current
#PY3  EQ2  18Mar91  18Mar91  #PK3  6937 hours, time
 
Ref Property Kind
SUIa Ref property type Ref property qualifier
#PK1 #PT1 Instantaneous
#PK2 #PT1 Permitted Maximum
#PK3 #PT2 -
 
Ref quantity property (subtype of Ref Property Type)
SUIa Name Ref Quantity Type Description
#PT1 Start Surge Current Electric current Maximum current drawn at a start up.
#PT2 Running hours Time Number of operating hours since new.

Inventory Storage

Model diagram EQW5: Equipment Inventory shows the concepts of inventory storage. The subtypes of  Inventory_object include items that have mass such as Equipment_item, Document and certain subtypes of  Material (i.e., Material_sample, Well_operation_fluid, Well_operation_solid and Other_material). Inventory_objects may be stored in a General_facility with the knowledge of that storage captured in Inventory_object_storage. Inventory_object_storage is a subtype of Transient_association which allows it to capture the start and end time of the storage and the Activities which resulted in the start and end of the storage. For example, a maintenance activity might terminate the storage of a pump in a warehouse and activate the installation of the pump in a pumping facility (see section Equipment and Material Installation).

The knowledge of who participated in an Activity associated with storing an Inventory_object can be captured in the association Business_associate_activity_role. This association has a relationship to Ref_business_associate_activity_role which states the role of the Business_associate in the Activity.

Each Inventory_object can have many names as defined in Inventory_object_alias. Each Inventory_object_alias is defined in a Ref_naming_system. Examples of Inventory_object_alias would be the identifiers or names placed on rock samples as they are recovered in a particular survey, or identification of samples at a laboratory, or identification of samples in storage. Note in this example, the same sample might have three names or aliases each allocated from a different naming system as control of the sample is transferred from Business_associate to Business_associate. A Ref_naming_system is often set up and controlled, and maintained by an organization. A specific object may have many names, each defined within a different naming system.

Where an inventory object has many aliases, one may be selected to act as an identifying name of the object. There is no guidance as to which alias to select as the identifying name, this is left to local implementation rules.

Facility Configuration

Facility Configuration shows the concepts of Facility, General_facility, Typical_facility and Facility_class. Typical_facility corresponds to the idea of a reusable design that defines some intended characteristics of a facility that may be defined in accordance with the design. For example, a gas treatment plant design with an operating pressure of 1000 psi and capacity of 30 MMscf/d may be defined as a Typical_facility. The design might be reused for each gas plant facility constructed for each field production center in an area.

Facility and General_facility allow business services or functions to be defined, independently of the physical equipment or materials that may be installed from time to time to perform the task or service. General_facility differs from Facility in that only General_facility and its subtypes participate fully in composition, connection and version associations. In the gas plant example, General_facility would be used to define Field A Gas Plant, to describe the functional capability to process gas produced at Field A. Facility_class defines criteria for classifying Facility and Typical_facility. It is similar to Equipment_class, a class has a range of characteristics that allow membership of the class to be determined. However, despite this definition, many classes can be defined without explicitly stating the characteristics. Examples of Facility_class would be commissioned, de-commissioned, etc. The interaction of these three concepts is illustrated in Figure 3.

 Facility / Class / Typical

Facility

Facility defines functional capability that may arise from the installation of Equipment_item and Materials. Facility is a token or concept used to describe the capability of equipment or materials. Facilities do not have mass, they are not physical objects. Only the Equipment_item or Materials that are installed to provide the service are physical objects.

Facility has an existence kind of actual, planned, required or predicted. The meanings of these terms in the context of facility are as follows:

Examples of Facility are shown.
 
General Facility (subtype of Facility)
SUIa Name Ref existence kind Description
#FC1  CG-LPG  Actual  Campo Grande LPG plant 
#FC2  Santa Cruz Field Center  Actual  Field center facility for the Santa Cruz field 
#FC3  SCZ-GT  Actual  High pressure gas dehydration facility at the Santa Cruz field. 
#FC4  CSC  Required  Gas condensate production facility at the Cascabel field. 
#FC5  SCZ-SP  Actual  Two stage condensate separation facility at the Santa Cruz field. 
#FC6  SCZ-LH  Actual  Condensate stabilization, storage and pumping facility at the Santa Cruz field. 
#FC7  SCZ-GI  Actual  Gas re-injection facility at the Santa Cruz field. 
#FC8  HPG-N  Actual  The system for producing and transporting HP gas in the North area. 
#FC9  LS  Actual  The system for producing and transporting crude liquids. 
 
The example shows the Campo Grande and Santa Cruz facilities to be actual, implying equipment and materials are installed and the service can or could have been provided. The Cascabel facility is required, meaning this describes a requirement for facilities. There may also be planned and actual facilities whose purpose is to meet the requirement.

Note the example instances describe locally used facility concepts. Other businesses use other facility concepts best suited to their needs e.g. GOSPs in Saudi Aramco, Gathering Centers in Kuwait Oil Co., Production Centers of National Iranian Oil Co. etc. All these would be examples of Facility.

Facility_composition associates Facilities as part of other Facilities. The association is valid for a period of time. A Facility may be described in terms of different Facilities as its function changes with time. For example, a gas injection facility may be added to central field facility after the production processing facilities are available.

Two types of Facility_composition are defined: Facility_assembly where the parts are dependent on each other in some way that may be described by connections, and Facility_collection where the parts are independent. A set of producing properties in a country, where no interdependence is implied, would be an example of a Facility_collection. An example of Facility_assembly is given using the Santa Cruz Field Center facility.
 
Facility Assembly
SUIa Whole Part Start time End time
#FA1  #FC2  #FC3  2Mar76  - 
#FA2  #FC2  #FC5  2Mar76  - 
#FA3  #FC2  #FC6  2Mar76  - 
#FA4  #FC2  #FC7  4Nov76  - 
#FA5  #FC8  #FC2  2Mar76  - 
#FA6  #FC9  #FC2  2Mar76  - 
 
Facilities may be part of more than one other General_facility. In the example, the Santa Cruz Field Center is part of the gas production system, HPG-N, and part of the liquids production system, LS, both being facilities.

Facility_connection enables General_facility to be connected to another General_facility. In the example of the Santa Cruz Field Center, the description could be expanded to include the information that the gas liquid separation component is connected to the gas treatment facility and to the condensate handling facility.
 
Facility Connection
SUIa To facility From facility Start time End time
#FX1  #FA5  #FA3  2Mar76  - 
#FX2  #FA5  #FA6  2Mar76  - 
 
Note either facility of the connected pair can be chosen for the to_facility and from_facility attributes. If material flow is to be described, the connections should be specified using the Facility subtype Product_flow_network_unit_port. This has specific characteristics that describe fluid flows.

Typical Facility

Typical_facility is a reusable facility design that defines some intended characteristics of facilities. Using the facility example, the operating company may develop a typical high pressure gas dehydration facility design for use in all appropriate new field developments. The design characteristics may be an operating pressure of 1000 psi, a capacity of 30 MMscf/d, and an inlet gas stream with less than 2% mol CO2 content.
 
Typical Facility
SUIa Name Description
#TF1  GDH-05  HP sweet gas dehydration 30 MMscf/d 
 
General Facility (with Typical facility added)
SUIa Name Ref existence kind Typical facility Description
#FC3  SCZ-GT  Actual  #TF1  High pressure gas dehydration facility at the Santa Cruz field. 
 
Typical_facility may be further described by defining its parts using Typical_facility_composition. This allows a facility design to be decomposed into its functional parts. So in the example, GDH-05 may be decomposed into an absorption tower design and a glycol regeneration facility design.

Facility Class

Facility_class defines criteria for classifying Facility and Typical_facility. The criteria provide a means of accepting or rejecting candidate members of the class. Facility and Typical_facility may have many classifications simultaneously or sequentially. Facility classes are often based on the service or function being performed. Some classes that may be relevant to the example facilities are listed.
 
Facility Class
SUIa Name Description
#FL1  Field Center  Land based facilities used to process well production or injection fluids in preparation for transport and sale. 
#FL2  Separation  A facility for separating well production into gas, hydrocarbon liquids and water streams. 
#FL3  Gas Separation  A facility for separating condensate liquids from gas. 
#FL4  Oil Separation  A facility for separating associated gas from oil. 
#FL5  Liquid Storage  A facility for storing liquid hydrocarbons. 
#FL6  Atmospheric Liquid Storage  A facility for storing liquid hydrocarbons at atmospheric pressure. 
#FL7  Pressurized Liquid Storage  A facility for storing liquid hydrocarbons at controlled pressures above atmospheric pressure. 
 
These might result in the example classification.
 
Facility Classification
SUIa Facility class Facility Start time End time
#FL11  #FL1  #FC2  -  - 
#FL12  #FL1  #FC3  -  - 
#FL13  #FL3  #FC5  -  - 
 
Facility_classes may also be classified as being members of other Facility_classes by the association Facility_class_classification.
 
Facility Class Classification
SUIa Be classified as Have as a member Start time End time
#FL15  #FL2  #FL3  -  - 
#FL16  #FL2  #FL4  -  - 
#FL17  #FL5  #FL6  -  - 
#FL18  #FL5  #FL7  -  - 

Equipment and Material Installation

Equipment and Material Use shows the involvement of Material and Equipment_item with Facility in the role of installation. Equipment_installation is an association defining an Equipment_item or Catalog_equipment as being installed to perform the function or service of a Facility. Note that if the equipment is being installed to perform only part of the function of a facility then that facility should be decomposed into smaller parts and the equipment should then be installed to perform the whole of the function of a component facility.

Using the previous examples, the Anvil type 23 pump (serial no 27458) might be installed in a pumping facility of the liquid handling facility of the Santa Cruz production center for the period 9Sep85 to 13Dec88, after which it was replaced by another pump, serial no BP7592 made by the Better Pump Co. The resulting data would be:
 
Pump (subtype of General_facility)
SUIa Name Ref existence kind Identifying facility Description
#FC10 Big Blue Pump Actual #FC6  -
 
Facility_assembly
SUIa Whole Part Start time End time
#FA7 #FC6 #FC10 - -
 
 Equipment_item_installation (subtype of Equipment Installation)
SUIa Equipment item Facility Start time End time
#EI1  #EQ1  #FC6  9Sep85  13Dec88 
#EI2  #EQ7  #FC6  14Dec88  - 
 
The nonconsumable use of material may also be described by Facility using the entity Material_installation. An example of this would be use of gravel in a gravel pack. Material_installation would record the installation of the gravel (also see Gravel_type).
 
Well_operation_solid (subtype of Material)
SUIa Identifier Ref existence kind Description
#MA1  -  Actual  Gravel, grade 24, 2027 lbs 
 
Gravel pack (indirect subtype of Facility)
SUIa Name Ref existence kind Description
#FC11  -  Actual  Completion gravel pack 
 
Material Installation
SUIa Material Facility Start time End time
#MI1  #MA1  #FC11  23Jul91  - 

Facility Subtypes

The subtypes Well, Wellbore, Well_completion, Wellbore_component_facility, Well_slot, Well_pattern, Product_flow_network_unit_port, Product_flow_network_group, Observation_definition and Seismic_facility cannot participate as the whole in the Facility_composition association. They may be parts of any Facility but their own component parts are described using particular relationships for each of the subtypes. Similarly these subtypes do not inherit relationships to Facility_connection, Typical_facility, nor Facility_version.

General_facility and its subtypes do not have these restrictions.

All subtypes of Facility may participate in a Business_associate_facility_association. This association defines the role (via Ref_business_associate_facility_role) of a Business_associate in a Facility. Examples of roles are drilling contractor, operator, safety officer, auditor, caterer, etc. These are functional roles in general, not job titles

Drilling Facilities

The major object used to conduct drilling operations is Drilling_facility. As the drilling and completions functions, in particular, specify purchase, maintenance, usage and disposal of a broad variety of types facilities, the Epicentre data model provides a number of subtypes of General_facilities for drilling. For example, the Drilling_rig superstructure is a General_facility assembled from parts which include the tower, drill floor, cables, pulleys, motors, compressors, etc. The Drillstring and its components are described in the Well Information topic.

The Drilling_facility may be described as an assembly of subtypes of General_facilities, such as:

The Drilling_facility is commissioned at the time the Drilling_rig and its configuration of parts is installed. Rig down would correspond to the decommissioning of the facility. This system also provides a simple mechanism for changing the rig at a site while maintaining the drilling facility, possibly in a suspended status. The same behavior applies to the various types of Drilling_facility with respect to the installation, removal of equipment in various capacities.


a SUI stands for System Unique Identifier. It is not part of the logical model and is used here as a convenient mechanism to uniquely identify each instance in the examples. An equivalent concept would be a DAE instance handle.

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