Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Operational research- main techniques PERT and CPM

this presentation mainly deals with operational research giving more focus on pERT and CPM techniques. this two methods are very useful and very confusing while reading but the examples in this presentation makes it very easy to understand this methods and for more study the end slide is provided with references.

  • Login to see the comments

Operational research- main techniques PERT and CPM

  2. 2. My Talks Today  History  Definitions  Operational Research(OR) Approach  Impact of OR on Policies  Critical Path method(CPM)/PERT  Queueing Model( Waiting Line Model)  Opportunities for OR in Health  Societies for OR  Funding Agencies for Operational Research  How to Obtain OR proposals  Conclusion
  3. 3. History  Even before India started its first five year plan, World had to witness the destruction and devastation of six years of Harakari during 2nd World War in 1939-45.
  4. 4.  In this six year devastation millions of deaths occurred and entire world in ruins, but it taught so many lessons to human being for human kind  And it led to the formal evolution of scientific tool that was going to revolutionized the research methodology in future. Operational Research
  5. 5.  During World War OR flourished for disaster but later on it flourished for development of Nation.  Prior to formal start of OR early work in OR was carried out by Charles Babbage in 1840  In relation to cost of transportation and sorting of mail that led to formation of England Universal Penny Post.
  6. 6.  Main credit for Operational Research goes to AP Rowe, who analyzed and improved the working of UK early warning radar system Chain Home.(1937) History
  7. 7.  Patrick Blackett is regarded as Father of OR.  Royal aircraft establishment through OR reduced no. of Anti Aircraft artillery rounds needed to shoot down enemy.  His team at Coastal Command’s OR section(CC- ORS) concluded that  A few large convoys are more defensible than many small ones.
  8. 8.  Aircrafts with white undersurfaces are not easily detected under clear clouds.  Bomber Command’s OR Section(BB-ORS) made logical recommendation that  Armor should be placed in the areas which were completely untouched by damage in the bombers which returned. History
  9. 9.  So till now we have discussed about the evolution of OR in fields other than Health.  OR came into action in Health, decades after its evolution just like timings of Indian railways. History
  10. 10.  Operational Research was first studied in Health Care settings in 1952.  In England , Norman Bailey published “Operational Research in Medicine” in the June issue in Operational Research Quarterly. (Bailey June 1952).  In the same year “Journal of the Operations Research Society” was launched in America. History
  11. 11. DEFINITION  WHO defines OR as the Systematic Research Techniques for program to achieve a specific outcome.  It provides policy makers and managers with evidence that they can use to improve program operations.
  12. 12.  Operational Research helps to identify solution to bottleneck that limit program quality, efficiency and effectiveness or  To determine which alternative service delivery strategy would yield the best outcomes.  Synonym of OR is Management Science.
  13. 13.  How OR is distinguished from other kinds of research????? 1. It addresses specific problem with specific program not general health issues. 2. Addresses problems that are under control of managers such as program system, training, pricing and provision of information. 3. It requires collaboration between managers and researchers in identification of the study and analysis & interpretation of results.
  14. 14.  In layman’s terms OR is defined as the application of scientific methods, techniques and tools  To problems involving the operations of a system so as to provide those in control of system with optimum solutions to problems.
  15. 15. Operational Research Approach
  16. 16. Impact of OR on Policies in US and CHINA  In US prevalence of Hepatitis B among general population is 0.1% as compared to 10% in Asian and Pacific Islanders.  An OR was done by INFORMS to evaluate cost-effectiveness of  Hepatitis B screening, vaccination, and treatment policies for adult Asian and Pacific Islanders in the US.
  17. 17. Policies for Decision Model 1. Status Quo – No formal policy. 2. Universal Immunization. 3. Screen, Treat and Vaccinate. 4. Screen and Treat. 5. Screen, treat and Ring Vaccinate.
  18. 18. Universal Immunization Screen, treat and vaccinate Screen and treat Screen, treat and ring vaccinate
  19. 19. Results
  20. 20. Dissemination and Impact  Shared results with US CDC  Published in a indexed medical journal  CDC changed screening recommendations in September 2008 1. − Persons born in geographic regions with chronic HBV prevalence>2%. 2. − US-born persons not vaccinated as infants whose parents were born in regions with >8% HBV prevalence.
  21. 21. HEPATITIS B in CHINA  Evaluate cost-effectiveness of HBV catch-up vaccination for children and adolescents in China.  140 million children unprotected
  22. 22. Vaccination Screen and Vaccinate
  23. 23. Results  Catch-up vaccination provides 1. − Better health outcomes 2. − Lower overall costs  Screening before vaccination is not cost- effective
  24. 24. Dissemination and Impact  April 2009: China changed its policy to provide free catch-up vaccination to all school age children 1. − Prevent ~70,000 deaths, save $900 million in health costs 2. − Reduce social injustice from discrimination
  25. 25. Critical Path method(CPM)  Critical path is the one which is having longest duration from starting to finish node. Program Evaluation and Review Technique(PERT)  Both CPM and PERT are nearly similar OR techniques except that duration is non deterministic in PERT.
  26. 26. Critical Path method(CPM)  Used in project management.  Shows how earlier project can be completed.  Inputs: 1. Activities 2. Duration (deterministic) 3. Precedence relationship  Outputs: Earliest time to finish project So while taking the example of Interns Hostel Chiri CHC which is under construction, lets suppose.
  27. 27. Expected time
  28. 28. Total = 79 weeks
  29. 29. Questions  1. How can the project be displayed graphically to better visualize the flow of the activities?  2. What is the total time required to complete the project if no delays occur? (44weeks)  3. When do the individual activities need to start and finish (at the latest) to meet this project completion time? (next slide)  4. When can the individual activities start and finish (at the earliest) if no delays occur? (next slide)
  30. 30.  5. Which are the critical bottleneck activities where any delays must be avoided to prevent delaying project completion? (A,B,C,E,F,J,L,N)  6. For the other activities, how much delay can be tolerated without delaying project completion?(Next slide)  7. Given the uncertainties in accurately estimating activity durations, what is the probability of completing the project by the 47 weeks? (PERT)
  31. 31.  Now Question 7  To find out probability of finishing project by 47 weeks ???  As we know that Variance = SD2  Therefore SD = 3  Z value = Due date–Estimated date/ SD = 47 – 44/ 3 = 1 Probability = 84.1%
  32. 32. Queueing Model( Waiting Line Models) Finite Queue Infinite Queue Single server Multiple Server Finite population Infinite population Balking Reneging Jockeying Lives on the Line
  33. 33.  Queueing principle FIFO  Lets assume Arrivals of clients = ƛ  Service provided = µ  Length of system/Queue = Ls, Lq  Waiting time in system/Queue= Ws, Wq Input ƛ , µ Output Ls, Lq, Ws, Wq
  34. 34. Questions  In immunization clinic suppose clients arrival is 8/hr, serving time is 9/hr then: 1. What is probability that no one is in system or server is free or server is not free? (Po= 11%) or (1-Po= 89%) 2. What is probability that there is no one in queue? (Po+P1= 21%) 3. What will the length of system/ queue? (Ls= 8 or Lq= 7.11) 4. What will be waiting time in system/ queue? (Ws= 1hr or Wq= 53 min)
  35. 35. Opportunities for OR in Health  Public health − Programs, policies making, disease prevention and control, health promotion, preparedness, ….  Health operations − Efficient operations of healthcare facilities, manpower planning and scheduling, supply chain management and contract design, infection control, …  Clinical decision making − Disease diagnosis and treatment, drug surveillance, individual patient decision making, …
  36. 36. Societies for OR  International federation of OR society (IFORS).  OR Society of India (ORSI).  Institute of OR and Management Science (INFORMS).  Centre of OR and Training (CORT).
  37. 37. Funding Agencies for OR 1. Bill and Melinda Gates Foundation 2. Council for Development of Social Science Research in Africa.(CODESRIA) 3. Global Fund to Fight AIDS, Tb, Malaria. 4. International Development Research center.(IDRC) 5. The US President’s Emergency Plan for AIDS Relief.(PEPFAR) 6. Rockfellar Foundation. 7. Wellcome Trust.
  38. 38. How to Obtain OR proposals Central Tuberculosis Division(CTD) Research Cell 1. Chief Medical Officer 2. Epidemiologist 3. Statistician 4. Data entry operator 5. Supporting consultant National Standing Committee on OR 1. Head of Prominent Institutes 2. Eminent Persons from the : • Centre of Excellence in field of medicine and research • CTD • Technical agencies
  39. 39. Zonal OR Committee 1. Zonal task force Chairman and member secretary 2. Member of State Task force from Zone 3. Member from Central Tb Institute 4. Statistician 5. Social scientist State OR Committee State Task Force chairman Medical College Representatives
  40. 40. Conclusion  Well the Silver Linings is that Operational Research is being more and more integrated as an essential part of monitoring and evaluation efforts in Public Heath.  Thus concept of M’OR’E could become a new paradigm for enhancing the practice of integrated monitoring and evaluation dimensions as one common component into program management system.
  41. 41. References  WHO. Modern management methods and the organization of health services, public health papers.  “Epidemiology and Management for Healthcare for All” By PV Sathe.  Framework for Operations and Implementation Research in Health and Disease Control Programs.  Malhotra S, Zodpey P. operation research in public health.Ind Journal Pub Health.2010:54(3)  Malhotra VM. Role of Game theory in Public Health. Online J Health Allied Scs. 2012;11(2):2.
  42. 42.  Thank you