DSS Lecture 2

7/30/2019 DSS Lecture 2

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Data and Model Management

An increasing focus on the value of data

to an organization pointed out that the

quality and structure of the databaselargely determines the success of a DSS.

A database organizes data into a logical

hierarchy based on granularity of the data.

The hierarchy contains four elements:

1. Database 2. Files

3. Records 4. Data elements


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Hierarchy of Data


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Database Management SystemDatabase - a collection of interrelated data organised to

meet the needs and structure of an organisation.

Data warehouse - combines various data sources into a

single resource.

Internal data

- transaction information systems

- Intranet - internal web-based system

External data- Internet

Private data


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Database Management System

Even though the data within each file havea common structure (the record), the filesthemselves may be quite diverse.

The important role of organizing the files

and databases goes to the DBMS. The two main responsibilities of the DBMS

are:

1. Coordinating the tasks related to storing andaccessing information.

2. Maintenance of the logical independencebetween the data in the DSS database and

the DSS application.


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General Functions DBMS

Data definition providing a data definitionlanguage and allowing for interrelation of

data

Data manipulation providing a querylanguage, allowing for capture and

extraction

Data integrity allows user to describerules that maintain integrity and check for

errors


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General Functions DBMS (cont.)

Access control allows identification of

users, controls access and tracks usage

Concurrency control provides procedures

for controlling the effects of simultaneous

access

Transaction recovery provides

mechanisms for restart and reconciliation in

the event of hardware failure


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Data Management Subsystem


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Model Base Management System

Model management subsystem includes

financial, statistical, management or othermodels and usually contains a modelling

language for building custom models. It is

managed by software called the model basemanagement system (MBMS).

A model is a simplification of some event

constructed to help study the event. The model base is the modeling counterpart

to the database; it stores and organizes the

various models the DSS uses in its analyses.


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Model-base management system MBMS

Transforms data from DBMS into useful

information

Prepare information for decision making

Raw Data

DBMS MBMS

Extract raw dataUseful Information


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General Functions of MBMS

Modeling language allows for creation ofdecision models, provides a mechanism for

linking multiple models

Model library

stores and manages all

models, provides a catalog and description.

Model manipulation allows for

management and manipulation of the modelbase with functions (run, store, query, etc.)

similar to those in a DBMS.


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Model Management Subsystem


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Four major categories:-

Strategic (long term) models:- support top managements

strategic planning responsibilities. Managerial (tactical) models:- assist in allocating and

controlling the organisational resources.

Operational models:- supports the day-to-day activities

of the organisation.

Model Building Blocks and Routines:-

- regression analysis

Other classifications: by functional areas

by discipline

DSS Lecture 2

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Transcript of DSS Lecture 2