While many engineering undergraduate courses are structured to introduce the theory related to various processes, students with no industrial experience have little sense of how this theory relates to real-life operations in the field. To address this concern, we set out to create a learning activity dedicated to help students relate theoretical concepts of process dynamics and control presented in class to their practical application in industry. Considering the prevailing trend towards a student-centred approach to pedagogy, we wanted to provide students with a basic simulation of system components. The program, designed to enable students to visualise the relationship between input variables and their effect on outputs, would engage the students in bridging the theory and concepts to meaningful application in practice. Hence, students could benefit from a learning activity that focused on a visual representation of the critical control elements in a simulated oil refinery furnace system. This article examines the design decisions in the development and evaluation of this learning activity, a web-based simulation for process dynamics and control education, and discusses the wider implications of online simulation interactivity features.

Dubbed ‘SimFurnace’, the program was designed to enable students to dynamically manipulate the inputs of a crude oil furnace in the upstream end of a refinery. While manipulating the fuel feed and feed flow rates of the system, students are able to observe the system’s responses. In the simulation freeform (practice) mode, students can also see how the formula calculation changes dynamically with input adjustments. Once students have had sufficient practice in the freeform mode, they can access a set of assignments designed to bring forth key process control concepts while problem-solving common industrial challenges. The program, developed using the Macromedia Flash MX authoring environment, is accessed from the university web servers at the convenience of the user. Srinivasan, Doiron, & Song (2003) offer a more in depth description of SimFurnace.

Considerations for Design

Before creating a simulation, the rationale and the aims of the project, the constraints and limitations in its development and implementation, and a review of existing programs all contribute to the initial graphic design and interactivity specifications. For example, the screen features and user input modes in SimFurnace are simple yet dynamic. Taking into consideration the limited scope of refinery operations being targeted and the fact that students were not expected to know every detail of chemical plant systems, a high fidelity system representation, such as those with complex and detailed displays available for industrial training, was not deemed necessary for meeting the learning objectives. However, emulating basic system dynamics was very important.

After a review of existing online programs designed to help students visualise process dynamics and control, we found that many online simulations were still stand-alone applications developed with Matlab/Simulink software. Applications created with such software have three major weaknesses:

1. Many programs process ‘batch’ type simulations in which the parameters/variables are specified at the beginning of the simulation run are not manipulated by the user during the course of the simulation.
   
   
2. The level of user interactivity with the model during the learning exercise is minimal.
   
   
3. The visualisation of the underlying process being simulated is limited: most use only simple state equations and block-diagram graphics to represent system elements and transfer functions. In most cases, there is no dynamic visualisation of the input/output relationship.

According to Fishwick (1995), these shortcomings are a serious impediment to the effectiveness of simulations as a learning tool. He emphasises that because computer simulations embody the principle of “learning by doing”, even a geometric model that looks good may not be satisfactory unless it has graphical representation of the system dynamics. Furthermore, these existing online simulations make little use of what Ranky, Bengu & Spak (1997) call “anthropocentric technologies” which, through intuitive interaction and immediate feedback, enable the learner to explore and implement concepts to a much deeper level.

Program Structure

A standard feature of simulation programs is a freeform interaction with the simulated system. This enables students to gain an intuitive sense of the interrelationships between the variables in the simulated process. In SimFurnace, students can direct the feed flow rate and the fuel flow rate into the system while monitoring and controlling the product output flow rate and temperature. The effects can be observed in real-time as the product flow rate and temperature are charted in the lower half of the screen. Students also have access to information on the system’s underlying logic, a first-order-plus-dead-time transfer function, and the ability to toggle the screen presentation to reveal a dynamic flow diagram of the process. This freeform section is also designed to familiarise the students with the simulation environment that they will encounter in another section: the assignment section (see Figure 1).

Although not all programs challenge the user to apply what they practise in the freeform interaction with the simulation, the design of assignment scenarios based on real-life problems is of utmost importance. In SimFurnace, the objective of having students complete the assignment section is to anchor their learning by getting them to instinctively react to system changes in a meaningful context. In doing so, students become aware of the relationship between real-life issues such as environmental factors and plant production requirements, and how these aspects of production affect the system input and output variables studied in class.

Figure 1: Assignment 4

Other Design Features

In order to provide feedback and some measure of control for the instructor, the design of online simulations should include a transparent tracking of user performance. As well as controlling access to the program, the instructor needs to enable and disable exercises, set new target ranges (parameters) for the simulations and control exercises, and browse student performance data and feedback comments. Hence an appropriate Learning Management System (LMS) needs to be considered (see Figure 2).

Figure 2: Custom Learning Management

Discussion

Taking into consideration what Yang & Alty (2002) describe as the “need to develop the student’s intuition for bridging the gap between theory and practice”, simple web-based simulations like SimFurnace can be created with existing off-the-shelf web authoring tools. Such customised web-based simulations, with a specific context and focus, can overcome the constraints of the classroom and enable students to associate concepts in theory with an experience of their meaningfulness in a setting related to their future profession.

Many new models for integrating online learning into the curriculum are needed and their appropriateness in meeting specific learning objectives in varied settings can only be assured through a systemic approach to creating online learning activities, designing meaningful interactivity, prototype testing and learning outcome validation. Using SimFurnace as an example, we have presented some of the design features that we believe help students relate classroom theory to practice in industry. Field trials investigating student learning gains from using SimFurnace are underway and preliminary results are encouraging.

References

Fishwick, P.A. (1995). Simulation Model Design and Execution: Building Digital Worlds. Prentice Hall. http://www.cise.ufl.edu/~fishwick/book/book.html (Last accessed 5 Jan 2004).

Ranky, P.G.; Bengu, G. & Spak, G.T. (1997). ‘The Development and Application of Synchronous and Asynchronous Technology Based Learning Aids for Undergraduate Engineering Education’. Proceedings of the National Science Foundation Engineering Education Innovators’ Conference, Arlington, VA, USA.

Srinivasan, R.; Doiron, G. & Song, M. (June 2003). ‘Enhancing Process Control Education using a Web-based Interactive Multimedia Environment’. In Computer-aided Chemical Engineering Vol. 15. Chen, B.Z. & Westerberg, A. (Eds.), Proceedings of the 8th International Symposium on Process Systems Engineering. Kunming, P.R.China. pp 1478–1483.

Yang, S.H. & Alty, J.L. (2002). ‘Designing a Multi-user Web-based Distributed Simulator for Process Control Learning’. In Grievnik, J. & van Schijndel, J. (Eds.), European Symposium on Computer Aided Process Engineering–12. The Hague, The Netherlands. pp. 1033–1038.