Priority ranges between 1 and 5. (b) The requirements engineer finds out if
a physical source contains the required data; if so, it is registered in the form
MAS_DS_P. (c) If a combination of fields yields some of the required data,
this combination is considered a logical data source, and it is registered in
the form MAS_DS_L. In our case study we have three physical data sources,
which for simplicity we denote A, B, and C. Data source A is a proprietary
system database, with transactional availability of 50% and priority 5 (contains
the core data of the business processes). Data source B is a SAP repository with
50% availability and priority 4. Data source C is a stylesheet collection (containing
monthly sales information) with availability 100% and priority 1.
??? Data.source.quality:.This step consists of three tasks that can be performed
in parallel. The goal is obtaining the quality of the data source for each datasource
combination. The data provider informs quality characteristics of the
data source and a mapping for the required fields (i.e., where is the required
data located, and under which name?).
??? Data.source.quality.(data):.The form DS_QTY_I is completed. This form
contains, for each query, for each data element in the query, and for each
data source, the following information: (a) mapping: field in the data source
containing the data element, or field to which a function must be applied.
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