360 likes | 523 Views
Applying System Dynamics Principles to CDEEP System MTP Presentation Rohit G ujrati 08305002 Guide: Co-Guide: Prof Sahana Murthy Prof. Sridhar Iyer CDEEP IIT Bombay CSE,IIT Bombay. Outline. Introduction Problem Definition System Dynamics Basics
E N D
Applying System Dynamics Principles to CDEEP SystemMTP Presentation Rohit Gujrati 08305002Guide: Co-Guide: Prof Sahana Murthy Prof. Sridhar IyerCDEEP IIT Bombay CSE,IIT Bombay
Outline • Introduction • Problem Definition • System Dynamics Basics • CDEEP : Current State of the art • CDEEP Model • Features of a System Dynamics Model • Conclusion & Future Work • References
Introduction • India produced 401,791 engineers in 2003-04 and in 2004-05, the number of engineering graduates increased to 464,743 [1]. • But only 25 per cent of them are employable[1]. • Main Reason : lack of well qualified teachers • Possible Solution : • Make IIT education accessible through Distance Education • Cost Effective • Global Reach
Introduction continued … • IITB has been running the distance education program since last 10 years. • Currently in the form of CDEEP to provide: • Good quality courses taught by IIT Bombay faculty • To everyone • At any place • Both synchronous and asynchronous modes • But number of students benefiting from CDEEP live courses has not increased as expected
Problem Definition • To model and analyse CDEEP system • To find out : • If there is any bottleneck resource • What–If analysis • If any policy changes needed • using System Dynamics • Why???
System Dynamics Basics • Computer simulation modeling for studying and managing complex feedback systems, such as business, engineering, and social systems • Think in terms of cause-and-effect • Focus on Feedback Loops • situation when output from an event will influence the same event in the future Study Grades Parents’ Expectations More More More
SD Modeling: Standard approach [2] • Identify the problem • Develop a dynamic hypothesis • Create a basic causal loop diagram • Convert the causal diagram to a Stock flow diagram • Write the equations • Estimate the parameters and initial conditions. • using statistical methods, expert opinion, market research data or other relevant sources. • Simulate the model and analyze results
Causal Loop Diagram • shows how one variable affects another. • nodes represent variables and arrows (called causal links) represent relationship • difficult to infer the behavior of a system only from its casual-loop representation Population Node time + Feedback Loop Causal Link
Stock and Flow Diagram • Distinguishes between different types of variables • Consists of three different types of elements: stocks, flows, and information Flow Stock Information
Stock and Flow Diagram cntd…. • SFD allows to represent relations among variables in terms of equations. • For Example • It becomes infeasible to solve as stocks and flows increase • Use computer simulators • Many simulators are available, (none is open source ) • We used Vensim PLE by Ventana Systems, Inc. [4] • Simulation result is time-history of variables • in terms of Graph/Table
CDEEP : Current State of the art • Distance Education through • Live Webcast and Satellite Transmission • Dynamic System with Feedback Loops • 4 studios for live webcast (only 1 for satellite ) • Live Webcast through Internet at 100 kbps for each connection • Not many students participating in this program
Our Work • Modeled Webcast and EDUSAT parts independently • Applied iterative approach to develop the model
Initial Webcast Model Causal Loop Diagram
Initial Webcast Model Stock and Flow Diagram joining new students Students Leaving
Simulation Results Bottleneck Equilibrium Consistently 1
Observations • Number of Students becomes constant (=200 student) after 24 months • Increasing number of courses doesn’t help • Bandwidth is the only bottleneck • Server is always underutilized • Limitations • MHRD grants can be used to bring in more resources, e.g. Bandwidth • Student feedback does matter • Marketing issues can not be ignored
Modified Webcast Model Causal Loop Diagram
Modified Webcast Model Stock and Flow Diagram Becomes 1 Gbps after 24 months From 4 to 6
Simulation Results Server Overloaded Huge increment due to increase in BW • One more here
Observations • Grants can be spent for different resources • Bandwidth increase much needed • If bandwidth is increased, server will become overloaded after 3 semesters • No. of courses limited by no. of studios • Marketing issues are very important • Feedback from students will influence no. of courses • Similarity of syllabus with other universities affects inflow
EDUSAT Model • Transmission through EDUSAT satellite • Dedicated 1 Mbps uplink and 500 kbps downlink • Student Interactive Terminals (SIT) for reception • Currently 72 Remote Centre (RCs), mostly engineering colleges • RC coordinators and Instructors to ensure proper functioning
EDUSAT Model Causal Loop Diagram
EDUSAT Model Stock and Flow Diagram
Results • Effect of relevance of courses
Results • Optimal: 20 courses and 0.7 marketing will reach 373 Number of courses vs. number of students Marketing vs. number of students after 18 months
Results • Effect of Distribution of Incoming Grants • Optimal mix : 20 courses and 0.7 on marketing Grants Enter Here
Observations • Attention needs to be paid on publicizing CDEEP programs and encouraging student to join CDEEP • Effect of grants visible after 12 months • Optimal mix : 20 courses and 0.7 marketing efforts
SDModel : Features • Current simulators are all proprietary applications • very limited collaboration among them • No truly successful open source System Dynamics model builder currently available. • Studied SystemDynamics Simulator[8] • Huge code without proper documentation • Prepared a higher level flowchart of a model and its constituent model components. • Referred an initiative SD Info Model[9]
System Dynamics Model Dark line shows containment Dotted line shows information flow
Conclusion • System Dynamics proved to be an important tool for modeling CDEEP system • Models were verified by CDEEP staff • Results obtained may help in improvement of existing system
Future work • Recommendations made may be validated by implementing them over the actual CDEEP system
Publication • Poster titled “Using System Dynamics to Model and Analyze a Distance Education Program” accepted in International Conference on Information and Communication Technologies and Development (ICTD) 2010.
References [1] McKansey Global Institute. Report on Emerging global labour market,2005. [2] John Morecroft, Strategic modeling and business dynamics: a feedback systems approach , Page no. 106 [3] Deepak B. Phatak Kannan M. Moudgalya and R. K. Shevgaonkar. Engineering education for everyone: A distance education experiment at IIT Bombay. Frontiers in Education, 2008. [4] System Dynamics Modelling, A Practical Approach, Chapman & Hall, 1996. [5] http://www.cdeep.iitb.ac.in/ [6] http://www.vensim.com/ [7] http://www.public.asu.edu/~kirkwood/sysdyn [8] http://sourceforge.net/projects/system-dynamics [9] http://sourceforge.net/projects/sdinfomodel