System Dynamics and Feedback Loop

In: Other Topics

Submitted By SissiChen
Words 1255
Pages 6
Topic: System dynamics and feedback loop
System dynamics is an approach to understanding the behavior of complex systems over time. It deals with internal feedback loops and time delays that affect the behavior of the entire system. System dynamics use feedback loops and stocks and flows to study complex and non-linear systems. Dynamics of the system contain quantities that vary over time.
There are several laws of Fifth Discipline showing how system dynamic works. 1) For every action, there is a reaction. It is self-proofed in the beer game. Every order has to be fulfilled, either in the current week (if enough stock is available) or in one of the next weeks (items go on backorder). 2) Short-term improvements often lead to long term difficulties. In the beer game, it’s always a tradeoff between fulfilling demand and minimizing cost. Timely delivery calls for enough inventory, while cumulative inventory results in climbing inventory cost, due to more people to handle the beer and more storage space, and there is also a possibility that the beer will be left in your inventory when the total period is over or the redundant beer might go bad since it cannot be kept long. 3) Cause and effect are not necessary closely related, either in time or in space. Sometimes solutions implemented here and now will have impacts far away at a much later time. In the beer game, it is not possible for any one component of the system to be immediately aware of the actions and needs of all other organizational components. A change of strategy for ordering can lead to a better condition, though may not be real-time. 4) The entirety of an issue is often more than the simple aggregation of the components of the issue. This is fundamental to understand how single parts in a system influence each other and how individual thinking differs from systemic thinking. The lesson…...

Similar Documents

Single Loop vs Double Loop Learning

...Single loop learning is the most common type of learning and involves problem solving and improving the system but does not seek any answers as to why the problem arose. On the other hand Double loop learning uses feedback from past actions to restructure the set assumption patterns and seek alternative solutions. It is necessary for higher order problem solving and leadership. We see a series of such examples in our daily lives, which involve the use of single loop and double loop learning techniques. As a part of this study we will be analyzing the use of these learning techniques in the implementation of e-governance projects and try to overview whether the replacement of single loop learning with the double loop learning techniques in these mission mode projects yielded better outcomes and results. The study will try to hit the target by being very specific and studying the RajSWAN (Rajasthan State Wide Area Network) Project. The government’s aim behind the implementation of RajSWAN project was to establish an effective communication infrastructure and create a highway for electronic transfer of information in the form of voice, video and data between the various departments of the state machinery with an aim to improve the administrative efficiency and effectiveness of Government programmes and schemes thereby resulting in an improved quality of service to the citizen of this state. It also aims to strengthen the disaster management capacity. RajCOMP is a State......

Words: 1026 - Pages: 5

System Dynamics over the Murray Darling Basin

...Introduction The Murray Darling Basin is the large catchment which covers 14% of Australia – Over one million square kilometres. It is located across four states – Queensland, New South Wales, Victoria, and South Australia. The area consists of the catchment for the Murray and Darling rivers and many tributaries with many high-value natural resources. The extensiveness of the wetlands support and maintain the health of the river system, which made the Murray Darling Basin the Australia’s most important agricultural area for both crop and livestock. As a result, the basin produces over one-third of Australia’s food supply. From above sentence, it seems that the area is enriched with healthy natural resources and ecosystem. However, during 2001 to 2009, the irrigation in this area has increased by a large number causing the low inflows in river systems. The low inflows including the climate change has resulted in the drought across the basin, followed by other environmental problems such as a degradation of biodiversity or an increase in salinity level of land and water, etc. Not only the environmental is destroyed but also the economic in the area which then causing the social impact. To resolve this issue, the government has established the Murray Darling Basin Authority (MDBA) in 2007 to address this problem and given a task to develop and implement a “Basin Plan”. However, for the current status, “The Proposed Basin Plan” has created the raging debate among the......

Words: 1631 - Pages: 7

360 Degree Feedback System

...Abstract The purpose of the paper is to provide an overview of the 360 degree feedback system and how the system may work within a restaurant. An in-depth analysis of the restaurant manager role and the relationship of the role with the 360 degree feedback system is explained in this paper. The process of implementation and the advantages and disadvantages of an implementation is explored before a recommendation is made. The recommendation is to implement the feedback system because an effective feedback system within the restaurant may help to promote growth. Keywords: 360 degree feedback system, restaurant manager 360 Degree Feedback System The 360 degree feedback system is a method of gathering feedback from various sources to include co-workers, customers, direct reports and other members of management. The method is confidential and usually administered through a questionnaire. The 360 degree feedback system gives managers the opportunity to rate themselves in a variety of Performance domains and, through feedback, to see how their self-assessment compares to the assessment of others (Flynn, Garavan & Morley, 1997). A self-assessment or the comparison of a self-assessment maybe used to help the manager develop. The objective is to develop employees within their current roles. Development does not always mean promotion but it is important that employees perform at their absolute best. Every employee is not a leader and some employees do not desire to......

Words: 1244 - Pages: 5

Using System Dynamics in Business Simulation Training Games

...Using System Dynamics in Business Simulation Training Games by Jennifer Ching-Wen Han Submitted to the Department of Electrical Engineering and Computer Science in Partial Fulfillment of the Requirements for the Degree of Masters of Engineering in Electrical Engineering and Computer Science at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY May 9th, 1997 © Massachusetts Institute of Technology, 1997. All Rights Reserved. Au th or ............................................................................. Departmenft-f Electrical Engineering and Computer Science May 9th, 1997 Certified by .... .................................. ................... Richard C. Larson _Th sis Supervisor Accepted by ........ ............ Arthur C. Smith Chairman, Department Committee on Graduate Theses ...... Using System Dynamics in Business Simulation Training Games by Jennifer Ching-Wen Han Submitted to the Department of Electrical Engineering and Computer Science May 9th, 1997 In Partial Fulfillment of the Requirements for the Degree of Masters of Engineering in Electrical Engineering and Computer Science ABSTRACT This thesis project includes researching and designing a system dynamics model for use in an existing Andersen Consulting Education (ACE) project management training game. This serves two major purposes. The first is to show how system dynamics can be used as a realistic and potentially superior method of business modeling. The second is to actually improve...

Words: 18414 - Pages: 74

Dynamic

...Part A Draw a CLD to explain the fish regeneration dynamics of ‘Lakeland Reserve’ based on the initial 500 fish in the Reserve area, assuming there is no fishing or other source of predation. Sketch a BOT graph as a reference mode that shows the pattern of change of the fish population over the 40 year period. Briefly explain the dynamics that your CLD reveals, any archetypal patterns of behaviour, and any other insights your initial analysis demonstrates. (This task has similar requirements to Assignment 1). BOT The BOT demonstrates the patterns of behaviour the fish population at ‘Lakeland Reserve’ over 40 years Year FISH POPULATION PATTERN OF BEHAVIOUR OF FISH POPULATION 500 1000 1500 2000 2500 3000 3500 4000 40 Figure 1 As shown in Figure 1, at the beginning (t=0) there are only 500 fishes. Hence, more fishes are added to the reserve and the fish population in the reserve keeps growing. The rate at which fishes are added is at an accelerating rate. However, when the reserve reaches its maximum capacity at 4000 fishes, the fish population starts to decline at a diminishing rate. CLD The CLD visualizes the interrelated variables in terms of the behaviour of fish population at ‘Lakeland Reserve’ during this period Figure 2 Figure 2, the casual loop diagram including three loops (two reinforcing loops and one balancing loop), demonstrates the fish regeneration dynamics of ‘Lakeland Reserve’ based on the initial 500 fishes in the......

Words: 447 - Pages: 2

System Dynamic Modelling

...1. Abstract System Dynamic Modelling is an approach to frame and solve complex problems. It is widely used for policy design and analysis. System dynamics analysis is a part of Systems Theory which is used to study the dynamic behaviour of complex systems. The theory is based on acknowledgement of the fact that the inter-relations between the various components of a model, time delays between processes are as important to analyse the behaviour of a model as is the analysis of individual components.  SD models solve the problem of simultaneity (mutual causation) by updating all variables in small time increments with positive and negative feedbacks and time delays structuring the interactions and control. In this paper, we have discussed the basic methodology of the technique, and the modelling process. Then, we have discussed the applications of SDM ranging from conventional ones like project management and science and engineering to exploring the concepts of SDM in Brand management and public health issues. 2. Historical background This technique of solving problems was developed in 1950s by Prof Jay Forrester of Massachusetts Institute of Technology, during his involvement with General Electric. He developed his insights about the foundations of engineering which helped him in the creation of system dynamics. He studied the problem of instability in GE employment. In this he did hand simulations (or calculations) of the stock-flow-feedback structure of the GE plants...

Words: 2058 - Pages: 9

A Virtual Reality Operator Interface Station with Hydraulic Hardware-in-the-Loop Simulation for Prototyping Excavator Control Systems

...Convention and Exhibition Center Singapore, July 14-17, 2009 A Virtual Reality Operator Interface Station with Hydraulic Hardware-in-the-Loop Simulation for Prototyping Excavator Control Systems Mark D. Elton, Aaron R. Enes, and Wayne J. Book, Fellow, IEEE Abstract— A multimodal operator interface station is developed to display a realistic virtual reality depiction of a compact excavator performing general digging tasks. The interface station includes engine audio feedback and a near life-size operator display attached to a full-size cab. The excavator dynamics are determined by models of the hydraulic system, the linkage system, and the soil digging forces. To maximize the fidelity of the hydraulic model, certain “virtual” components of the model are replaced with real-time hardware-in-the-loop (HIL) simulations of the actual hardware. HIL simulation is done in a geographically isolated facility, with Internet based communication between HIL and the Remote Operator Interface. This is the first reported high-fidelity operator interface to be combined with remote hydraulic HIL simulations. I. I NTRODUCTION Hydraulic hardware has undergone a great evolution in recent years, evolving from purely hydro-mechanical devices to electro-hydraulic systems controlled by microprocessors. The use of electronic controllers opens the door to improving dynamic performance and enhancing traditional hydraulic off-highway construction machines with new features such as increased energy......

Words: 4674 - Pages: 19

Feedback

...[pic]Feedback: Transactions - week 2 This is a feedback page. Please review this page carefully because later pages in this practice set build on the feedback provided here. After you have reviewed your feedback page, click Continue at the bottom of this page to move on to the next page of your practice set. Your progress [pic] |[pic] Completed: |24% (approximately) | |[pic] Remaining pages will take: |up to 16 hours | The time frames we provide are a guide only. It may take you more or less time to complete each step. Your grading |Your grading outcome (still in progress) | |  |Awarded |Total | |Points (prior to this page) |212 |238 | |Points (on this page) |183 |219 | |Points (after this page) |− |824 | |Total |395 |1,281 | |  | Information from previous pages ▪ General instructions ▪ Policies and procedures ▪ All transactions ▪ Adjusting entries information ▪ Trial balance - May ▪ Schedules of accounts - May ▪ Inventory cards - May ▪ Bank reconciliation - May ▪ Bank statement - June ▪ Special printing information ▪ Journals and ledgers instructions ▪ Inventory cards instructions You are now instructed to record transactions that occurred throughout......

Words: 2725 - Pages: 11

Solution for Classical Dynamics of Particles and Systems

...CHAPTER 0 Contents Preface v vii Problems Solved in Student Solutions Manual 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Matrices, Vectors, and Vector Calculus Newtonian Mechanics—Single Particle Oscillations 79 127 1 29 Nonlinear Oscillations and Chaos Gravitation 149 Some Methods in The Calculus of Variations 165 181 Hamilton’s Principle—Lagrangian and Hamiltonian Dynamics Central-Force Motion 233 277 333 Dynamics of a System of Particles Motion in a Noninertial Reference Frame Dynamics of Rigid Bodies Coupled Oscillations 397 435 461 353 Continuous Systems; Waves Special Theory of Relativity iii iv CONTENTS CHAPTER 0 Preface This Instructor’s Manual contains the solutions to all the end-of-chapter problems (but not the appendices) from Classical Dynamics of Particles and Systems, Fifth Edition, by Stephen T. Thornton and Jerry B. Marion. It is intended for use only by instructors using Classical Dynamics as a textbook, and it is not available to students in any form. A Student Solutions Manual containing solutions to about 25% of the end-of-chapter problems is available for sale to students. The problem numbers of those solutions in the Student Solutions Manual are listed on the next page. As a result of surveys received from users, I continue to add more worked out examples in the text and add additional problems. There are now 509 problems, a significant number over the 4th edition. The instructor will find a large...

Words: 97501 - Pages: 391

Performance Evaluation and Feedback System

...Performance Evaluation and Feedback System (PEFS) Objective: Introduce the difference of PEFS between Japan and the west Goal: Understand the reason and result of adoption of different PEFS Expected result: Able to work in a company with the PEFS which is suitable for them. Japan: Staff performance is evaluated as a whole, based on company profit, department contribution. Feedback and future direction is provided to all staff in company / department through group meeting (e.g., morning assembly). The reason of using this PEFS is that Japanese pays attention to relationship, and their career goal is group/company success. When compensation is based on individual performance, staff becomes focus on individual success. This hampers team working and company success. As a result, staff works under strain of the working environment (self-control), strives to maintain good relationship with others (focus on harmony), follows custom and finds a middle way to solve any problems (avoid conflict). As it is difficult for staff to express his own opinion in working environment, building relationship becomes more important for personal success. This creates the “after work drinking” culture. The West: Staff performance is evaluated as a whole and individual basis, based on company profit, department contribution, and individual performance. Feedback is provided to individual. One on one meeting is held to discuss career goal and development plan. The reason of using this......

Words: 324 - Pages: 2

Systems Dynamics

...ASSIGNMENT 1 SUBJECT: SYSTEMS DYNAMICS CODE: SDN411T DATE: 25TH FEBRUARY 2015 Department: Industrial Engineering Lecturer: mr o.a. makinde, Room 2-337 Please note that this Assignment will only be uploaded on MyTutor SDN411T until the 7th April (Day and Evening Class) at 000hrs and not at any later times! MARKING This assignment carries a weighting of 25% of the marks for this subject. Sections will be weighted individually as follows: TASKS | | TOTAL MARKS | 1 | | 60 | 2 | | 110 | Overall Presentation | Summary, Introduction, Report Flow, References, etc. | 10 | TOTAL MARKS | 180 | Objective: To write a report that covers the items listed below. The report should include sketches and diagrams wherever these are relevant. A maximum of 15 sides of A4 script would be satisfactory with font size 12 Times Roman and 1.5 line spacing. 1. APPLICATIONS OF SIMULATION 1.1 Investigate two different manufacturing and servicing industries in South Africa and other countries in the global world where simulation has been applied. Note: Each of these industries should be from two different manufacturing and servicing industries. Your investigation should clearly indicate the following (though not exclusively so); 1.2.1 When simulation was adopted in each of these industries [4] 1.2.2 How has simulation been carried out in each of the industries identified? (The methodology) ...

Words: 729 - Pages: 3

Earth-System Feedbacks in Response to Volcanism

...The Earth system consists of the geosphere, atmosphere, hydrosphere and biosphere, and can be regarded as a large-scale example of Le Chatelier's Principle where systemic perturbations are mitigated through complex feedbacks to eventually establish an amended equilibrium. The geosphere impacts the other spheres as it regulates uniformitarianism through volcanism, while also providing the physical interface between the lithosphere and organic subaerial constituents of the earth system in the form of regolith; thereby facilitating biotic subsistence and terrestrial feedback. Considering spatiotemporal impacts of volcanism are inherently interconnected concerning volcanism, a temporal scale will be implemented to define such feedbacks between parameters of the earth system, as the Gaia Hypothesis postulates. It is evident that short-term impacts (<1 year) deriving from major eruptions are interrelated and therefore impact the Earth systems’ spheres in a variety of complex ways. For instance, ejecta that fails to penetrate the stratosphere exacerbates tropospheric meteorological activity in the succeeding weeks as tephra acts as a nuclei for water vapour, which is subsequently precipitated out (10). This rain encompasses particulate sulphide matter that impacts the biosphere (via regolith) by acidifying soil pH levels, that in turn kills enzymes and insects while intensifying leaching of essential nutrients (Mg, Ca) through clay degradation (12). Phreatic hydromagmatic......

Words: 1592 - Pages: 7

Stochastic Modeling of an Automated Guided Vehicle System with One Vehicle and a Closed-Loop Path

...504 IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING, VOL. 5, NO. 3, JULY 2008 Stochastic Modeling of an Automated Guided Vehicle System With One Vehicle and a Closed-Loop Path Aykut F. Kahraman, Abhijit Gosavi, Member, IEEE, and Karla J. Oty Abstract—The use of automated guided vehicles (AGVs) in material-handling processes of manufacturing facilities and warehouses is becoming increasingly common. A critical drawback of an AGV is its prohibitively high cost. Cost considerations dictate an economic design of AGV systems. This paper presents an analytical model that uses a Markov chain approximation approach to evaluate the performance of the system with respect to costs and the risk associated with it. This model also allows the analytic optimization of the capacity of an AGV in a closed-loop multimachine stochastic system. We present numerical results with the Markov chain model which indicate that our model produces results comparable to a simulation model, but does so in a fraction of the computational time needed by the latter. This advantage of the analytical model becomes more pronounced in the context of optimization of the AGV’s capacity which without an analytical approach would require numerous simulation runs at each point in the capacity space. Note to Practitioners—This paper presents a model for determining the optimal capacity of an automated guided vehicle (AGV) to be purchased by a manufacturer. This paper was motivated......

Words: 8654 - Pages: 35

Improving the Inventory Levels of a Blood Supply Chain Through System Dynamic Simulation

...Jurnal Teknologi Full paper Improving the Inventory Levels of a Blood Supply Chain Through System Dynamic Simulation Jafar Afshar*, Narjes Sadeghiamirshahidi, Ali Reza Firouzi, Seyed Mojib Zahraee, Syed Ahmad Helmi Syed Hassan Faculty of Mechanical Engineering, Department of Industrial Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia *Corresponding author: amir_1065@yahoo.com Article history Abstract Received :1 January 2014 Received in revised form : 15 February 2014 Accepted :18 March 2014 The blood supply chain is a complex system with a multi-echelon structure. Hence, the integration of various interconnected elements, which should be synchronized appropriately, is a necessity to meet the patients’ requirements. The performance of the blood supply chain is a function of different variables that are dependent of each other. Therefore, the main aim of the chain is the optimization of the overall supply chain by considering the dynamic behavior of the system. The purpose of this study is to develop a system dynamic simulation model for a complex blood supply chain in order to improve the average level of inventories. The developed model is based on three echelons with a centrality on a regional blood center. The performance of the supply chain network in the current condition is investigated and based on the objectives, 17 scenarios were experimented for improving the average level of inventories to......

Words: 2709 - Pages: 11

Customer Feedback Systems

...Customer feedback systems (CFS) are extremely useful in capturing the voice of the customer. A good CFS makes it easy for them to give feedback, and in addition enables effective service recovery and establish appropriate compensation levels. These allow an assessment and benchmarking of of the service quality and performance, drive learning and improvements, and create a customer service oriented service culture. When capturing the voice of the customer, many tools are available, such as market surveys, service feedback forms, mystery shopping and focus group discussions. The reason why a whole variety of tools have been developed is that they each have different strengths and weaknesses. Service marketers need to tailor and select a relevant mix of tools to jointly deliver the needed information. For instance, total market surveys and annual surveys measure satisfaction with all major customer service processes at a high level in order to obtain a global indicator of overall service satisfaction. However, they do not tell whether customers are happy or unhappy. They are also brief and unable to address issues in greater detail due to the sheer scope covered. Transactional surveys on the other hand are conducted after a specific service has been completed like immediately after a meal. This allows a more in depth questioning and could include open ended questions such as what you like best or like worst to improve the service. It is more actionable and tells whether the......

Words: 413 - Pages: 2