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. skills Most of you will not get a job to, explicitly, do I.E. stuff Rather, you will be hired to help your company, your client, or your company’s client make decisions Your 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 tools DSS goal – to improve the effectiveness of decision making

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 tools DSS goal – to improve the effectiveness of decision making

Decision Support Systems 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.

Decision Support Systems 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

Decision Support Systems 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

Decision Support Systems Don’t try to dazzle your user with technical sophistication You DSS might be used by various people, with various skill levels Be careful about the assumptions that you make regarding the user’s skills

Decision Support Systems 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

Decision Support Systems Hide the technical detail from the user Have the technical detail available, on demand Organize your interface in appropriate sized chunks In the end, you DSS (and you) will be judged on its usability and the clarity of its results

Decision Support Systems 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 records Information – data in context, has meaning, it must tell you something So, if I give you – 39 That’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

Data, Information and Metadata Metadata – data about data It describes data, its formats, properties, characteristics In a sense, a template that defines what the data is Data ElementTypeSizeDescription IDNumber10Student Id No. NameText15Student Name BirthDateDate8Birth Date RankText2Class Rank

Data, Information and Metadata 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

Storing and Using Data 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

Storing and Using Data 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 process You define models of the thing you are building a database about… … from a data standpoint

DataBase Development 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 Modeling 1. Using step 1, 2. What are the entities and relationships that exist among these entities 3. Use entity-relationship modeling

DataBase Development 3. Logical DataBase Design 1. Translate Entity-Relationship models to definitions of tables, their properties – schema 4. DataBase creation and construction 1. Implement database in DBMS 2. Create tables, fields, properties, etc 3. Define relationships 4. Build queries, forms, reports,… 5. Tune

DataBase Development 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,…

DataBase Development 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