Improving Decision-Making Support

Transcription

1 Improving Decision-Making Support by Linking Database results to Simulations Gio Wiederhold Stanford University May 2014 Gio Wiederhold SimQL 1

2 Problem : Mismatch Database Technology should support Decision-Making What does database technology do? o Databases provide information about past events» Consistent» Reliable» Fast What does a decision-maker do? o Guess how decisions will affect the future» Multiple possibilities» Uncertainty» Slow, manual, multiple tools Gio Wiederhold SimQL 2

3 Decision-making (DM) Analyze Alternatives Current Capabilities Future Expectations Planning for them Process tasks: List resources Enumerate alternatives Prune alternative Compare alternatives now future Gio Wiederhold SimQL 3

4 Current Processes Data conversion to files for spreadsheets. Model building and testing by analysts Planning for likely future scenarios Recording expected results. Data collection Comparing many scenarios. Data validation Finding the best plans. Data integration Advising the actual. Information selection decision maker Data reduction & summarization File generation for analysts Gio Wiederhold SimQL 4

5 Support for planners There are dozens of business-software packages they have their own files o sometimes databases» sometimes even schemas Spreadsheet use dominates because of ease of use o and clarity of process Actionable information people don t just want big data people want to have answers for decision Gio Wiederhold SimQL 5

6 Current state of DM Support past now future organized support Data integration Databases ffga jjkl,a nsnd nn 23.5a disjointed support Intuition + Spreadsheets Resource allocations Explicit simulations various point assessments distributed, heterogeneous Past future time Gio Wiederhold SimQL 6

7 The Future is not just one line past now future time Support of decision-making requires dealing with the future, as well the past Databases deal well with the past Sensors can provide current status Spreadsheets, simulations deal with the likely futures Information systems should be able to combine all three Gio Wiederhold SimQL 7

8 DM support is disjoint does not interoperate Planning Science Distribution extensions to move to networked support are also disjoint Gio Wiederhold SimQL 8

9 Share schemas 1. Take a some software package, or spreadsheet app 2. Let it access information from some big data source 3. Expand the DB schema with parameters needed to make predictions 4. Support access to multiple sources 1. Driving times 2. Weather 3. Accident reports to predict arrival times of shipments 1. Population health statistics 2. Individual record to select treatment Gio Wiederhold SimQL 9

10 Prediction Requires Data & Tools this book, Alfred Knopf, 1997 Gio Wiederhold SimQL 10

11 Q & A Gio Wiederhold SimQL 11

12 Requirements Ubiquitous access to simulations of a wide variety of types Rapid response to parameter changes o Access to up-to-date facts o May need High-Performance recomputation Model, scenario, and choice retention o Analysts planning to be reused» But updatable Gio Wiederhold SimQL 12

13 Progress in Data Integration Information Integration has progressed in supporting Decision Making 1. Integrate data from distributed sources o Issues: inconsistency of scope and timing 2. Capture new relationships o Often requires expert inter-domain knowledge 3. Include current sensor data o Select streaming data 4. include predictions about future courses ******* A new, potentially major topic ******* Gio Wiederhold SimQL 13

14 How to merge 2 disciplines Databases o High-level languages» Data descriptions o Drive detailed processes o Intentional Simulations & spreadsheets o High-level languages» Model desriptions o Parameter driven o Extensional Gio Wiederhold SimQL 14

15 Integration concept Enable intentional simulation access o Follow database model» Similar to data description o Provide interfaces»to support needed processes Create SimQL similar to SQL schema & links to access procedures Gio Wiederhold SimQL 15

16 Transform Data to Information Database Design Data Collection Schema oo -) SQL user Reports middlemanagement :-( Model Design Data-driven Modeling :-) o o value-added services decision-makers Plans Gio Wiederhold SimQL 16

17 Language implementation Stanford Experiment uses an existing SQL parser: 1. Replace the SELECT verb with ESTIMATE; 2. Remove the UPDATE statement. Nothing persists 3. Replace CREATE DATABASE with CREATE MODEL; 4. Add to the CREATE attributes IN, OUT, and INOUT; 5. Add a REGISTER statement to identify resources; 6. Replaced SQL s functions code generators that access stored data with functions that deliver the a. Query IN parameters to various simulations b. Collect the data specified as OUT parameters c. Return the result. Gio Wiederhold SimQL 17

18 Examples SQL: SELECT Temperature, Cloudcover, Windspeed, Winddirection FROM WeatherDB WHERE Date = `yesterday' AND Location = `ORD'. SimQL: ESTIMATE Temperature, Cloudcover, Windspeed, Winddirection FROM WeatherSimulation WHERE Date = `tomorrow' AND Location = `ORD'. Gio Wiederhold SimQL 18

19 Available Functions 1. Continously executing: weather prediction o SimQL result reports best match samples 2. Execution specific to query: Spreadsheet what-if assessment o may require HPC power for adequate response 3. Past simulations collect results in a base: materials o performs inter- or extra-polations to match query parameters 4. Combinations, i.e., : top layer simulation using stored partial lower level results: weapon performance in new setting 5. Human-in-the-loop: Wrapper for Amazon s Mechanical Turk Note A simulation service program can be written in any language A simulation service must be compliant to the interface spec. Gio Wiederhold SimQL 19

20 System Concept Layout Gio Wiederhold SimQL 20

21 Interfaces enable integration: SimQL to access Simulations past now future time Databases, accessed via SQL or XML, CORBA compliant wrappers Simulations, accessed via SimQL and compliant wrappers Msg systems, sensors Gio Wiederhold SimQL 21

22 Current State of SimQL research GUI collect language requirements Test Application wrapper wrapper wrapper Spreadsheets Weather Engineering Gio Wiederhold SimQL 22

23 Stanford Experiment Models Logistics Application Manufacturing Application SimQL access wrapper SimQL access wrapper SimQL access SQL access wrapper wrapper Spreadsheets Weather (short-, long-term) Test Data Engineering Gio Wiederhold SimQL 23

24 More to be done Stanford experiment only produced point results. A decision maker would estimate multiple scenarios 1. Collect results identified with parameters 2. Provide search functions to compare results 1. Consider time lines for result synchronization 3. Support pruning of low-value results 4. Deliver only high-value results to decision-maker Gio Wiederhold SimQL 24

25 Use of Simulation Results time prob Simulation results can be composed for alternative Courses-of-actions Composition should include computation and recomputation of likelihoods Likelihoods change as now moves forwards and eliminates earlier alternatives. Gio Wiederhold SimQL 25

26 Estimates have probabilities p=30% chance of rain Flight p=91% likely to arrive with 15 min of ETA Interest rate p=50% same, p=25% 1% higher,. Employee p=50% returns to work in a week,. Project p=10% completed in time, Spreadsheets can compute alternative values with such data provided by the model builder, not the SimQL user. Gio Wiederhold SimQL 26

27 The branches can be labeled with probabilities, then assessed using the outcome with values value prob Next period alternatives and subsequent periods past now future time Values Gio Wiederhold SimQL 27

28 Integrating data & planning support will make our data reusable and much more valuable Re-assess as time marches forward! A Pruned Bush ? past now future?? time Databases,... Spreadsheets, other simulations, Msgs sensors Gio Wiederhold SimQL 28

29 Even the present needs SimQL last recorded observations point-in-time for situational assessment simple simulations to extrapolate data past now future time Not all data are current: Is the delivery truck in X? Is the right stuff on the truck? Will the crew be at X? Will the forces be ready to accept delivery? Gio Wiederhold SimQL 29

30 Use of Simulation Results Simulation results can be composed for Alternative Courses-of-actions Composition should be seamless, elegant, with computation and recomputation of likelihoods Results change as now moves forwards and eliminates earlier alternatives. Gio Wiederhold SimQL 30

31 Summary Databases serve clients via SQL by Sharing a Model (The Schema) A query language over the model the SQL interface enables independence of application development DBMS technology development reuse of infrastructure Today most new systems use a DBMS for data storage even with less performance, inability to handle all problems, but enough of them well enough. Simulations should serve clients via SimQL by Sharing a Model (research q.) A query language over the model a SimQL interface enables independence of application development simulation technology develop t reuse of infrastructure Objective build information systems combining DBMS, Simulations even with less performance, inability to handle all problems, but enough of them... Gio Wiederhold SimQL 31

32 Further research questions How to move seamlessly from the past to the future? How can multiple futures be managed (indexed)? How can multiple futures be compared, selected? How should joint uncertainty be computed? How can the NOW point be moved automatically? Gio Wiederhold SimQL 32

33 Future information systems Combine data from the past, with current data, knowledge, and predictions into the future o o o o o o Assessment of the values of alternative possible outcomes Gio Wiederhold SimQL 33

34 SimQL research questions How little of the model needs to be exposed? How can defaults be set rationally? How should expected execution cost be reported? How should uncertainty be reported? Are there differences among application areas that require different language structures? Are there differences among application areas that require different language features? How will the language interface support effective partitioning and distribution? Gio Wiederhold SimQL 34

35 Moving to a Service Paradigm Server is an independent contractor, defines service Client selects service, and specifies parameters Server s success depends on value provided Some form of payment received for services x,y Databases are a current example. Simulations have the same potential. Gio Wiederhold SimQL 35

36 Summary of SimQL A new service for Decision Making: follows database paradigm ( by about 25 years ) coherence in prediction displacement of ad-hoc practices seamless information integration single paradigm for decision makers simulation industry infrastructure investment has a potential market should follows database industry model: Interfaces promote new industries Gio Wiederhold SimQL 36

37 Publications Gio Wiederhold: "Information Systems that Really Support Decision-making"; 11th International Symposium on Methodologies for Intelligent Systems (ISMIS), Warsaw Poland, June 1999, in Ras & Skowron Foundations for Intelligent Systems, Springer LNAI 1609, pages Gio Wiederhold and Rushan Jiang: Augmenting Information Systems with Access to Predictive Tools ; The specifics of the language as implemented are at Gio Wiederhold SimQL 37