IE 423 – Design of Decision Support Systems Introduction to Data Base Management Systems and MS Access

IE 423 – Design of Decision Support Systems

Introduction to Data Base Management Systems and MS Access

Announcements

Midterm Exam – March 3, 2008 That’s one week from Today

By now you should have

Read Chapters 1,2 & 3 in Pol and Ahuja

Revisit some thoughts about Decision Support Systems

By now, all of you have developed a wide range of I.E. skillsMost of you will not get a job to, explicitly, do I.E. stuffRather, you will be hired to help your company, your client, or your company’s client make decisionsYour I.E. skills will be the tools that you will use to accomplish this

Decision Support Systems

DSSs do not replace or supplant the human in the decision making process Rather to augment the human

DSSs = Human judgment X information technology based toolsDSS goal – to improve the effectiveness of decision making


DSSs do not replace or supplant the human in the decision making process Rather to augment the human

DSSs = Human judgment X information technology based toolsDSS goal – to improve the effectiveness of decision making


There is a pretty good probability that the user of your DSS will be: VP Marketing Production manager Planning department … But not you …and not, in most cases, an I.E.


So, you will design and build a DSS… Using sophisticated analytic methods,

algorithms, simulations, models, forecasts and extensive data

Your user will want to know what your tools do,…

… but not how they work If they do, they will ask


So, you will design and build a DSS… Using sophisticated analytic methods,

algorithms, simulations, models, forecasts and extensive data

Your user will want to know what your tools do,…

… but not how they work If they do, they will ask


Don’t try to dazzle your user with technical sophisticationYou DSS might be used by various people, with various skill levelsBe careful about the assumptions that you make regarding the user’s skills


Your DSS should be attractive, well designed, relevant to the situation…must be easy to use Take advantage of appropriate user

interface controls Organize the interface logically

Things that belong together functionally should be presented together


Hide the technical detail from the userHave the technical detail available, on demandOrganize your interface in appropriate sized chunksIn the end, you DSS (and you) will be judged on its usability and the clarity of its results


Five Components of a DSS Database – information that can be

applied to the decisions Model base – models, methods,

algorithms that can be applied to the decisions

Knowledge base – expertise that can be applied the decisions

GUI – The users view of the system (like a filter)

User – the decision maker

Data, Information and Metadata

Data – discrete pieces, facts, things recordsInformation – data in context, has meaning, it must tell you somethingSo, if I give you –

39That’s data, but what does it mean?If I tell you that is my age, then it is information Age=39

OK, its not true, but you get the idea


Metadata – data about data It describes data, its formats, properties,

characteristics In a sense, a template that defines what the

data is

Data Element

Type Size Description

ID Number 10 Student Id No.

Name Text 15 Student Name

BirthDate Date 8 Birth Date

Rank Text 2 Class Rank


Metadata – data about data Tells us about the data Helps us to understand what the

data means Applies to all data of the same

class Contains no data

Storing and Using Data

File based systems Keep each kind of information in a

separate file Student ID info in one file; student

grades in another file; student class schedule in another file

Files are discrete entities in their own right


File based systems - Problems Duplicate data – the student name may

have to be entered and stored in each file

Linkages between files must be done in application software

Structure of files “hard-coded” in application software

Inflexible – difficult to make changes Can’t use in dynamic manner


DataBase Management Systems DataBase - Collection of related data

Like a collection of files in file based systems

DBMS – software to create, use and manage databases

DataBase Applications – software that employ the DBMS to use the data in DataBase

DBMS

Data Independence Separation between data and its

definition and applications that use it Concurrency control – allow multiple

user to access data, safely, keeps things clean

Replication services – keeps data across DB in sync

Utility Services – tools to support the creation and management of databases

DataBase Development

DataBase development starts with a modeling processYou define models of the thing you are building a database about…… from a data standpoint


1. Enterprise Modeling – 1. what are the major components of the

system?2. What has to be built,3. …and what already exists

2. Conceptual Modeling1. Using step 1, 2. What are the entities and relationships that

exist among these entities3. Use entity-relationship modeling


3. Logical DataBase Design1. Translate Entity-Relationship models to

definitions of tables, their properties – schema

4. DataBase creation and construction1. Implement database in DBMS2. Create tables, fields, properties, etc3. Define relationships4. Build queries, forms, reports,…5. Tune


Entity-Relationship modeling – in a nutshell

Define entities People, Houses, Cars

Define the properties of each entity People – names, age, address Houses – type, No. of rooms, address Cars- make, models, year, color,…


E-R modeling – in a nutshell (cont.)

Define the properties of each entity People – names, age, address Houses – type, No. of rooms, address Cars- make, models, year, color,…

Define relationships between/among entities People have addresses – houses have

addresses

Documents

IE 423 – Design of Decision Support Systems Introduction to Data Base Management Systems and MS Access