SCM-Based Client/Server
Technology Application Example
The example illustrates full cycle of information system
development using SCM/SCQL and the client/server technology. The example covers
a part of a Manufacturing Execution System of a metallurgical production. The
core concept of the production is material unit – a metal piece. The key
requirement made for systems of such class is the following: the system is to
store data about all existent material units (raw materials, intermediate and
final products) and full history of their processing. During production a
material unit undergoes the following transformations: slabs can be cut, coils
can be cut or welded, plate packs can be formed from different coils as it is
shown on the figure 1. Transformation operations occur on production units; one
material unit can be produced only by one production unit and can be consumed
for making other material units only by one production unit.
Figure 1. Transformation of Material Units
During Processing
A material unit can be assigned to a commercial
order for which the unit is being produced. Production units are special cases
of production divisions. Production divisions form a hierarchy according to
subordination.
SCM Model of a Metallurgical
Production in Textual Notation
The following SCM model covers the
described above part of the example information system. Here application domain
names are bold. When one application domain uses another application domain,
the “Use” phrase is applied. The detailed description of the used SCM textual
notation can be found at [Ov04-3].
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General. Physical Object Physical
Object Moment General. Physical Object.
Geometry Physical
Object has a Thickness ® Physical
Object has a Width ® Physical
Object has a Space Position ® General. Physical Object.
Gravity Physical
Object has a Mass ® Physical
Object has a Weight ® General. Physical Object.
Chemical Composition Physical
Object has a Carbon Concentration ® Production. Material Unit Use
General. Physical Object. Geometry Use
General. Physical Object. Gravity Material
Unit has a
Thickness ® Material
Unit has a Width ® Material
Unit has a Mass ® Material
Unit may be assigned to a Commercial Order ® Material
Unit is produced
at a Producing Production Unit ® Material
Unit is consumed at a Consuming Production Unit ® Producing
Production Unit
is a Production Unit º Consuming
Production Unit
is a Production Unit º Material
Unit has a [ Production. Commercial Order Use
General. Physical Object Use
General. Physical Object. Gravity Commercial
Order has an
Optimal Mass ® Commercial
Order has an
Optimal Date ® Optimal
Mass is a Mass º Optimal
Date is a Moment
º Production. Production
Division Subordinate Production Division is a Production Division º Higher
Production Division
is a Production Division º Subordinate
Production Division is nested to a Higher Production Division ® Production
Division has a
Full Name º Production
Unit is a
Production Division º Production
Unit has an
Average Capacity ® Production. Indiscrete Use General. Physical Object. Gravity Use
Production. Material Unit Mass
Transition is
from a Consumed Material Unit ® Mass
Transition is to
a Produced Material Unit ® Mass
Transition has a Mass ® Consumed
Material Unit is
a Material Unit º Produced
Material Unit is
a Material Unit º Production. Indiscrete. Metallurgic Use
Production. Material Unit Use
General. Physical Object. Chemical Composition Slab is a Material Unit º Slab has a Carbon Concentration ® |
During ER model creation we have taken some decisions. The result ER
model being equivalent to the SCM model defined above is the following.
Figure 2. ER Model of the MES Part
The Appropriate Relational Model
A relational model generated from the ER model
is represented at the figure 3. Here, all attributes have been named according
to their senses.
Figure 3. Relational Model of the MES Part