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--- modeling_of_activities_and_processes [2018/11/01 13:56]
andries [2. Specification of how objects are involved in occurrences]
+++ modeling_of_activities_and_processes [2018/11/01 14:27]
andries [4. Specification of activity sequences]
@@ Line 35: / Line 35: @@
 ====== 3. Definition of kinds of occurrences, activities, processes and events ======
-Occurrences that do not exist yet in the Gellish English dictionary can be added in a similar way as defining physical objectsby obeying the [wiki:"Proper definition of a concept" rules for proper definitions] in Gellish English. A kind of occurrence shall be defined as a subtype of an existing kind of occurrence and facts that are by definition true shall be added to complete the definition. \\
+Occurrences that do not exist yet in the Gellish dictionary can be added in a similar way as defining physical objects by obeying the [wiki:"Proper definition of a concept" rules for proper definitions]. A kind of occurrence shall be defined as a subtype of an existing kind of occurrence and given a textual description, whereas facts that are by definition the case shall be added to complete the definition. \\
-In general, generic kinds of activities and processes are independent of the subject of the occurrence, and independent of the performer or the enabler. For example, the activity 'design' or 'operate' does not include an indication of what is designed or operated. However, more specialised ‘qualified’ activities often do include the subject of the activity or process. For example, "design a pump" or "operate a facility". In such a case the definition of such a kind of occurrence should include and explicit relation that states that it has by definition as subject a particular kind of thing. For example: \\
+Note that there is a distinction between generic kinds of occurrences and kinds of occurrences that have by definition an intrinsic performer or enabler. In general, generic kinds of activities and processes are independent of the subject of the occurrence, and independent of the performer or the enabler. For example, the activity 'design' or 'operate' does not include an indication of what is designed or operated. However, more specialized ‘qualified’ activities often do include the subject of the activity or process. For example, "design a pump" or "operate a facility". In such a case the definition of such a kind of occurrence should include and explicit relation that states that it has by definition as subject a particular kind of thing. For example the concept 'design a pump' is defined as follows: \\
-^Name of left hand object^Name of relation type^Name of right hand object^
+^Name of left hand object^Name of kind of relation^Name of right hand object^Partial definition^
-| design a pump | is a qualification of | design|
+| design a pump | is a qualitative subtype of | design|where the subject is a pump.|
-| design a pump | has by definition as subject a | pump|
+| design a pump | has by definition as subject a | pump| |
-Similar considerations apply for specific activities that include a specific subject. For example, the specific activity called 'design P-101" is by definition a design of a thing called P-101. This is specified as follows: \\
+Similar considerations apply for individual activities that include a specific individual object as its subject. For example, the activity called 'design of P-101" is by definition a design of a thing called P-101. This is specified as follows: \\
-^Name of left hand object^Name of relation type^Name of right hand object^
+^Name of left hand object^Name of kind of relation^Name of right hand object^
-| design of P-101 | is classified as a | design of a pump
+| design of P-101 | is classified as a | design of a pump|
-| design of P-101 | has as subject | P-101
+| design of P-101 | has as subject | P-101|
+Note that the kind of relation 'has by definition as subject a' classifies a relation between two kinds, whereas the kind of relation 'has as subject' classifies a relation between two individual things.
 ====== 4. Specification of activity sequences ======
-Often it is required to specify in which sequence activities or chains of shall be or are performed. This may result in activity networks. For example, in activity scheduling for testing, commissioning and start up of facilities or to describe a maintenance procedure. This can be done for sequences of kinds of activities, but also for sequences individual activities, or for procuderes in which typical activity sequence is describedthat shall be repeated every time that the procedure is followed. \\
+Often it is required to specify in which sequence activities or chains of activities shall be or are performed. This may result in activity networks. For example, a sequence of activities that specifies a schedule for testing, commissioning and start up of a facility or the activity sequence that describes a maintenance procedure. Sequences can be specified for kinds of activities, but also sequences of individual activities, or in procedures in which a typical (individual) activity sequence is described that shall be repeated every time that the procedure is followed. \\
-For example, the following activity sequence may describe steps that shall be taken during a planned maintenance shut-down (also called a turnaround) of facility:
+For example, a generic activity sequence that describes steps that shall be taken during a planned maintenance shut-down (also called a turnaround) of facility may specify a sequence of kinds of activities. For example as follows:
-^Name of left hand object^Name of relation type^Name of right hand object^
+^Name of left hand object^Name of kind of relation^Name of right hand object^
 | purge a vessel | shall occurs after a | drain a vessel|
 | inspect a vessel | shall occurs after a | purge a vessel|
-Whereas a sequence of individual activities is expressed as follows:
+Typical activities are activities about individual things. Usually they are modeled as individual activities. When used in a procedure, the represent imaginary activities, whereas the real activities repeatedly use the procedure as a template. A sequence of typical individual activities uses other kinds of relations than above. Such a detailed procedure is expressed as follows:
-^Name of left hand object^Name of relation type^Name of right hand object^
+^Name of left hand object^Name of kind of relation^Name of right hand object^
 | assemble system A | occurs after | clean system A|
 | test system A | occurs after | assemble system A |
+Further details, for example about specifying partly overlapping activities, are given in the book 'Semantic Information Modeling Methodology'.
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