Simulation and Modelling 2 – Problem Formulation

1. Simulation and Modelling2 – Problem Formulation Yumarsono Muhyi STMIK Supra Even Semester 2008/2009 May 12th, 2009

2. About Me • Yumarsono Muhyi • Head of Information System Dept., STMIK Supra • Undergraduate of Electrical Engineering, Telecommunication - ITB • Management Magister, Sistem Informasi - UPN (final semsester dan thesis) • Research Field: Computation, Operational Research, Optimation, Simulation • y.muhyi@gmail.com (email and chat) • y.muhyi@yahoo.com (mostly chat) • 0856-9117-2669 / (021) 93131-633

3. Lessons • Introduction • Formal Problem Statement • Orientation • Project Objectives

4. 1. Introduction • Goal: understanding what is to be accomplished by performing the study. • The activities: • A formal problem statement • Orientation of the system • Establishment of specific project objectives

5. 2. Formal Problem Statement • Goal: • Provide both the practitionerand the potential audience with a clearly understandable high-level justification for the simulation. • The goal including: • Increasing customer satisfaction • Increasing throughput • Reducing waste • Reducing work in progress

6. Increasing Customer Satisfaction • Increasing customer satisfaction is of fundamental interest in any system involving service operations. • This type of system typically includes waiting or processing queues. • Reductions in queue time usually result in increased customer satisfaction. • Customer satisfaction may also involve delivering products when promised. • Reductions in the number of tardy jobs will reduce operating costs associated with the loss of goodwill and will increase customer satisfaction.

7. Increasing Throughput • Increasing throughput involves the amount of products or number of jobs that can be processed over a given period of time. • This can involve the elimination or improvement of different process operations. • It can also include the identification and redesign of bottleneck processes.

8. Reducing Waste • Reducing waste results in reduced operating costs and increased net profits. • Waste can be reduced throughreductions in spoilage and obsolescence. • Spoilage can involve processes that are time and temperaturecritical. • Obsolescence waste can result from an organization’s inability to bring its product to the marketon time.

9. Reducing Work in Progress • Work in progress is work that requires further processing for completion. • Work in progress is commonlyfound in processes that require multiple discrete operations. • Work in progress typically requires storagebefore the next process can be carried out. • Reducing work in progress reduces process costs associatedwith resource capacity and storage requirements. • Large amounts of work in progress can result frominsufficient resource capacity or poor operating policies. • Reducing work in progress can decrease thespace needed for manufacturing or distribution facilities.

10. Tools for Developing the Problem Statement • Fishbone/Cause-Effect/Ishikawa Chart • The Fishbone chart is also known as the cause-and-effect diagram, man–machine–material chart, andas the Isikawa chart (Suzaki, 1987). • The purpose of this chart is to identify the cause of the problem oreffect of interest. • Pareto Chart • The Pareto chart is a second technique to help the practitioner to develop the problem statement. • It may turn out that there are several sources or causes of the problem or problems ofinterest. • This is frequently referred to as the80–20 rule: 80% of the problem is caused by 20% of the factors.

11. Fishbone Chart

12. Pareto Chart

13. 7 Basic Quality Control Tools • Histogram • Pareto Chart • Check Sheet • Control Chart • Flow Chart • Fishbone/Cause-Effect/Ishikawa Chart • Scatter Plot

14. Histogram

15. Check Sheet

16. Control Chart

17. Flow Chart

18. Scatter Plot

19. 3. Orientation • Goal: The practitioner’s familiarizing himself or herself with the system. • Orientation Process/Types: • Initial orientation visit • Detailed flow orientation visit • Review orientation visit

20. Initial Orientation Visit • Goal: To obtain a high-level understanding of the basic inputsand outputs of the system. • It is important not to attempt to understand too much detail of thesystem in the initial visit. • After the initial orientation visit, the practitioner should immediately reflect on the major componentsof the process while recollection of the visit is still fresh.

21. Detailed Flow Orientation Visit • Goal: An understanding of how the system operates. • The practitioner should make detailed notes on thesystem operation by recording: • The types of entities that are processed by the system • The number and type of queues • The number and type of system resources • The sequence of processes as experienced by the entities • How the system performance can be measured

22. Review Orientation Visit • Goal: To ensure that the understanding of the systemoperation is consistent with the practitioners’ understanding of the system and/or flow chart.

23. Tools for The Orientation • High degree of access to the system. • Recording devices: • Digital camera (pictures, photos) • Camcorder (video) • Tape recorder, mini recorder (sounds) • Computer activity recorder

24. 4. Project Objectives • Project objectives are dynamic. • Common project objectives may involve • Performance-related operating policies • Performance-related resources policies • Cost-related resource policies • Equipment capabilities evaluation

25. Decision-Making Tools for Determining Project Objectives • Brainstorming: to generate a storm of ideas • Brainstorming preparation • Brainstorming process • Electronic brainstorming (email, chat, forum, etc.) • Nominal group technique • Al of the participants have the opportunity to vote on what theybelieve is the most important project objective. All of the participants are given an equal number of voteto cast. • Delphi process • Serves the same function as the nominal group technique. All voting is conducted anonymously after the brainstorming session has concluded. The administrator distributes a list of all of the brainstorming ideas. Theparticipants then vote for a particular idea. At the end, the administrator retainsonly a set of the most popular ideas.

26. The End • Discussion. • Question and answer. • Case study.