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Decision Support Technology. DSS Reference Architecture Language System Problem Processing System Knowledge System Presentation System.

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Presentation on theme: "Decision Support Technology. DSS Reference Architecture Language System Problem Processing System Knowledge System Presentation System."— Presentation transcript:

1 Decision Support Technology

2 DSS Reference Architecture Language System Problem Processing System Knowledge System Presentation System

3 Outline Knowledge system technology –data management –data warehousing –Data marts –online analytic processing (OLAP) ROLAP, MOLAP, WOLAP

4 Evolution of DSS Transaction Processing Systems (TPS) –Operational data stores and OLTP –Batch reports, hard to find and analyze information, inflexible and expensive, reprogram every new request (circa 60s) MIS –Management reporting from transactions in TPS –Still inflexible, not integrated with desktop tools (circa 70s) DSS –Combine data with analytic models or expert rules –Integration with desktop tools (80s)

5 Evolution of DSS Data Warehousing –Data integrated after (cleaning and scrubbing) from multiple sources (both internal and external to the organization) –OLAP is the technology used to study the data in terms of operations on a multi- dimensional data set –Data warehousing also supports processing of data by analytic methods and permits data mining (90s)

6 Applications Retail - inventory management, promotions Manufacturing - order shipment Insurance – policy and claims tracking Telecommunications - call analysis Financial – account tracking CRM/eCRM – customer profiling, clickstream analysis Healthcare – disease management, patient and physician profiling

7 Disease Management Programs Address health quality of population by identifying at-risk members and applying prevention programs Challenge: identifying at-risk members Data warehouses can help with this effort Aetna U.S. Healthcare Members with certain ailments are flagged using an algorithm that examines members diagnoses, procedures, laboratories, and pharmaceuticals Data gathered from medical and pharmaceutical claims, member and provider profiles (nearly 3 terabytes) Results: reduction in frequency of acute asthmatic episodes, improvements in vaccination rates

8 Data Model A representation scheme with which to describe data: data relationships, data semantics, and consistency constraints. Examples –ER (entity relationship model) –Relational model –Object-oriented model References: – m (ER model) m – (MS Office product tutorials) – (MS Access tutorial)

9 E-R schema: A simple example physician patient evaluates mn -Modeling the structure of data, not the processing of it

10 ER Schema: a detailed example

11 Relational model Primary model used today for data- processing applications Database systems like Oracle, Sybase, Informix, MS SQL server etc. support this model Based on a well understood theoretical model

12 Example of a relational schema: Physician(doc_id, d_name, specialty) Patient(p_id, p_name) Evaluates(doc_id, p_id, date, diagnosis) An Example

13 Essential features of the relational model A relational model schema consists of relations or tables Each table has a set of fields (columns) that are related to one another One or more fields whose values determine the value of other fields are called keys Tables are normalized in order to remove redundancies

14 New Data Types Text, images, video, audio, time series, spatial, …. Other, more exotic data types like fingerprints (an IBM Extender) and face recognition (an Informix DataBlade). Offered by IBM, Informix, Oracle

15 Object-oriented Databases Objects belong to object classes determined by the structure (variables) and behavior (methods) of the object - not easy to represent in a relational database Methods that impact the state of the variables of the object are encapsulated within the object and facilitate interaction between objects eg. Object bank account modifies balance by amount Potentially reduced development and maintenance time

16 From Databases to Transaction Processing The real state is represented by an abstraction, called the database, and the transformation of the real state is mirrored by the execution of a program, called a transaction, that transforms the database. Source: Jim Gray,MSFT

17 Examples Point of sale systems –credit card transactions ATM machines –all withdrawals and deposits E-commerce web sites Health Care –medical records, billing

18 Databases for Decision Support Transaction Processing systems are optimized for performance Data they capture are too detailed to be of use for decision support purposes Online Analytical Processing (OLAP) imposes very different demands on databases than does Online Transaction Processing (OLTP)

19 Data Analysis: An Example Reimbursements Net Profits Mill 52.4 Mill 3.2 Mill5.2 Mill % Inc

20 Reimbursements Net Profits Mill 52.4 Mill 3.2 Mill5.2 Mill % Inc North South East West Reimb. by region 7.2 Mill 13.4 Mill 18.4 Mill 6.4 Mill 7.5 Mill 18.4 Mill 17.4 Mill 9.1 Mill Data Analysis: A Hospital Example

21 Specialty A Specialty B Specialty C Specialty D Reimb. - South by specialty 2.65 Mill 6.45 Mill 3.1 Mill 1.2 Mill 2.70 Mill 7.10 Mill 4.0 Mill 4.60 Mill North South East West Reimb. By region 7.2 Mill 13.4 Mill 18.4 Mill 6.4 Mill 7.5 Mill 18.4 Mill 17.4 Mill 9.1 Mill Data Analysis: An Example

22 Reimbursements Net Profits Mill 52.4 Mill 3.2 Mill5.2 Mill % Inc North South East West Profits by region 0.88 Mill 1.12 Mill 1.1 Mill 0.1 Mill 0.50 Mill 2.60 Mill 0.13 Mill 1.97 Mill Data Analysis: An Example

23 Reimbursements Net Profits Mill 52.4 Mill 3.2 Mill5.2 Mill % Inc Specialty A Specialty B Specialty C Specialty D Profits-South by specialty 0.20 Mill 0.60 Mill 0.22 Mill 0.10 Mill 1.20 Mill 0.40 Mill 0.90 Mill Data Analysis: An Example

24 Integration System Collects and combines information from disparate sources Provides integrated view, and a uniform user interface Supports sharing of data between entities World Wide Web Digital LibrariesScientific Databases Personal Databases Heterogeneous Database Integration

25 Why look at data in this way? –What would be the demand for services (forecasting)? –Who are our key customers/patients, and –What are the margins/outcomes? (profitable customers/satisfied patients) –How do we market to them/treat them? –What pricing/treatment strategy is desirable? –What are their preferences? –What type of customer/patient services are required? –What services when packaged result in higher/better sales/revenues/margins/outcomes, efficient workflow? –Which promotion/patient education/counseling works or does not work and why? –What is the inventory/patient turnover? –Which channel/technology is more effective/profitable? –Why do margins/outcomes differ from one place to another or one patient to another?

26 Customer Relationship Management ANALYZE TAKE ACTION DISCOVER Source: Pilot Software Customer base Profitability Buying pattern Support pattern Productivity Policies & Procedures Marketing policies Support procedures Trends in market Selling opportunities Opp. For improvements

27 Business Intelligence Software applications, technologies, and analytical methodologies that perform data analysis Often used as a broad term that includes OLAP, data mining, query, reporting tools and technologies

28 Business Intelligence Loop Business Strategist OLAPData MiningReports Data Storage Extraction, Transformation, & Cleansing CRMClinical ISPharmacyLab Data Warehouse Decision Support

29 Data Warehouse A decision support database that is maintained separately from the organizations operational databases. A data warehouse is a –subject-oriented, –integrated, –time-varying, –non-volatile collection of data that is used primarily in organizational decision making (W.H. Inmon)

30 Why Separate Data Warehouse? Performance Operational databases are designed & tuned for known transactions & workloads. Complex OLAP queries would degrade performance for transactions. Special data organization, access & implementation methods needed for multidimensional views & queries Function –decision support requires historical data (up to 5 to 10 years of data) –consolidation of data from many operational systems and external sources –data quality considerations (semantic and measurement issues are resolved)

31 Local vs Central Data Repository LocalCentral Data Warehouse Repository Knowledge Generation Local Rules Base Local Data Knowledge Generation HIS Data Other Data Sources Central Data Feedback Option Forward Data

32 Warehouse Database Schema ER design techniques not appropriate Design should reflect multidimensional view –Star Schema –Snowflake Schema –Fact Constellation Schema

33 Multidimensional Data Model Database is a set of facts (points) in a multidimensional space A fact has a measure dimension –quantity that is analyzed, e.g., sale, budget A set of dimensions on which data is analyzed –e.g., store, product, date associated with a sale amount Dimensions form a sparsely populated coordinate system Each dimension has a set of attributes –e.g., owner, city and county of store Attributes of a dimension may be related by partial order –Hierarchy: e.g., street > county >city –Lattice: e.g., date> month>year, date>week>year

34 Example: Patient profiling A healthcare organization needed a longitudinal view of patients, including trends of services to patients Model Facts include Healthcare (e.g., diagnosis, procedure), Financial (e.g., amount billed, number of claims), Resources (e.g., number of bed-days, inpatient and outpatient visits) Dimensions include Time, Provider, Claim Type, Demographics, Encounter Type, Diagnosis and Procedure, Person, Organization Questions answered by system: Which individuals are eligible for services but not obtaining them? Which individuals are registered for services, but not receiving preventive healthcare?

35 Example of a Star Schema Order No Order Date Customer No Customer Name Customer Address City SalespersonIDSalespersonNameCityQuota OrderNOSalespersonIDCustomerNOProdNoDateKeyCityNameQuantity Total Price ProductNOProdNameProdDescrCategoryCategoryDescriptionUnitPrice DateKeyDate CityNameStateCountry Order Customer Salesperson City Date Product Fact Table

36 Star Schema A single fact table and a single table for each dimension Every fact points to one tuple in each of the dimensions and has additional attributes Does not capture hierarchies directly Straightforward means of capturing a multiple dimension data model using relations

37 Example of a Snowflake Schema Order No Order Date Customer No Customer Name Customer Address City SalespersonIDSalespersonNameCityQuota OrderNOSalespersonIDCustomerNOProdNoDateKeyCityNameQuantity Total Price ProductNOProdNameProdDescrCategoryCategoryUnitPrice DateKeyDateMonth CityNameStateCountry Order Customer Salesperson City Date Product Fact Table CategoryNameCategoryDescr MonthYear Year StateNameCountry Category State Month Year

38 Snowflake Schema Represent dimensional hierarchy directly by normalizing the dimension tables Easy to maintain Saves storage, but may reduce effectiveness of browsing (Kimball)

39 Fact Constellation Store Key Product Key Period Key Units Price Store Dimension Product Dimension Sales Fact Table Store Key Store Name City State Region Product Key Product Desc Shipper Key Store Key Product Key Period Key Units Price Shipping Fact Table

40 Fact Constellation Multiple fact tables share dimension tables. This schema is viewed as collection of stars hence called galaxy schema or fact constellation. Sophisticated applications require such schema.

41 Data Warehouse vs. Data Marts Enterprise warehouse: collects all information about subjects (customers, products, sales, assets, personnel) that span the entire organization. –Requires extensive business modeling –May take years to design and build Data Marts: departmental subsets that focus on selected subjects: Marketing data mart: customer, products, sales. –Faster roll out, but complex integration in the long run.

42 Virtual Warehouse Views over operational databases –Materialize some summary views for efficient query processing, easier to build, requisite excess capacity on operational database servers

43 Data Warehouse Architecture Clinical System Payroll System Billing System External Data Other Internal Data (e.g., AS400) Oracle Financials on HP 9000 Access, Files (Industry Reports) Transformation Integration Data Warehouse Meta-Data ExcelWebOther Data Mining Tools OLAP servers

44 Extraction, Transformation, & Load (ETL) ETL is a set of tools and techniques used to populate a data warehouse Extraction Extract data from sources (e.g., operational DBMSs, file systems, Web pages) Transformation Clean data Convert from legacy/host format to warehouse format (e.g., convert surname to last name)

45 Extraction, Transformation, & Load (ETL) Load Sort, summarize, consolidate, compute views, check integrity, build indexes, partition Huge volumes of data to be loaded, yet small time window (usually at night) when the warehouse can be taken off-line Techniques: batch, sequential load often too slow; incremental, parallel loading techniques may be used Refresh Propagate updates from sources to the warehouse When to refresh - on every update, periodically (e.g., every 24 hours), or after significant events How to refresh – full extract from base tables vs. incremental techniques

46 Metadata Types of Metadata Administrative metadata source databases and their contents gateway descriptions warehouse schema, view & derived data definitions dimensions, hierarchies pre-defined queries and reports data mart locations and contents data partitions data extraction, cleansing, transformation rules, defaults data refresh and purging rules user profiles, user groups security: user authorization, access control

47 Metadata … Types (continued) Business data business terms and definitions ownership of data charging policies Operational metadata data lineage: history of migrated data and sequence of transformations applied currency of data: active, archived, purged monitoring information: warehouse usage statistics, error reports, audit trails Tools: Platinum Repository (Computer Associates) Meta Directory (Information Builders)…

48 The Complete Decision Support System (Source: Franconi) Information SourcesData Warehouse Server (Tier 1) OLAP Servers (Tier 2) Clients (Tier 3) Operational DBs Semistructured Sources extract transform load refresh etc. Data Marts Data Warehouse e.g., MOLAP e.g., ROLAP serve Analysis Query/Reporting Data Mining serve

49 Three-Tier Architecture Warehouse database server –Almost always a relational DBMS; rarely flat files OLAP servers –Relational OLAP (ROLAP): extended relational DBMS that maps operations on multidimensional data to standard relational operations. –Multidimensional OLAP (MOLAP): special purpose server that directly implements multidimensional data and operations. Clients –Query and reporting tools. –Analysis tools (excel) –Data mining tools (e.g., trend analysis, prediction)

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