Data elements form the basis of sales and marketing information systems. They define what is actually recorded in the system. Examples include the number of hats from a different manufacture in Mr. B store. A data element assigns a certain meaning to the table fields and is defined over a domain while a field is defined over an element.
Data elements must conform to ISO/IEC 11179 metadata registry and should consist of the following primary parts; element ID, name of the element, aliases, specification of base or derived elements and length of the element. Others include object property, type of data and representation. The object may be left out when the property is within the objects context. However, a qualifier may be used when necessary to uniquely identify an element.
For example columns on Mr. ProductOrders will be expressed as
Product_order Number Sold Rem
Hat_manufacturer3 5 1
Hat_manufacturer4 7 4
Hat_manufacturer5 2 1
Hat_manufacturer6 2 9
Data structure dictionary
A data structure dictionary is created using algebraic notation and provides a vivid view to the analyst on the elements that make up a data structure. For instance, Mr. Bush wants a data structure dictionary that outlines the different parts that makes a package of camping kits.
The camping kits data structure can be represented as shown below. It is used to classify and order PRODUCT PARTS for the manufacture of the camping kits.
Each PRODUCT PART screen comprise of entries found on the right hand side of the = sign. Some entries are elements while other such as ADDRESS, TELEPHONE, and SUPPLIER NAME are groups of elements or structural records. Structural records must be broken down into data elements at the lowest level.
The definition of the PRODUCT PART screen is definition for each structural record. The same applies for TELEPHONE NUMBER where the area code and other particulars are defined.
PRODUCT PART = Product Name+
Order Date +
(Available Product Items)+
Merchandise Total +
Shipping and Handling +
Order Total +
Method of Payment+
(Credit Card Type) +
(Credit Card Number) +
Supplier Name = First Name +
Telephone = Area Code+
Available Products Items = Quantity needed+
Price per part+
Method of delivery = [Air: Water: Road, Charge: Check]
Check Details = [Name; Bank Details: Branch: City]
Method of payment = [Check: Charge: Online transfer]
Online transfer = [Michael Bush: Online Transfer: Visa]
Gary B. Shelly, T. J. (2011). Systems Analysis and Design: Eighth Edition. Cengage Learning .
Harrington, J. L. (2002). Relational database design clearly explained . Morgan Kaufmann,.