a compiler for business simulations: toward business model development by yourselves

A compiler for business simulations:Toward business model development

by yourselves

Kazuhiko Tsuda a,*, Takao Terano a, Yasushi Kuno a,Hiroaki Shirai b, Hisatoshi Suzuki a

a Graduate School of Systems Management, University of Tsukuba, Bunkyo-ku 3-29-1,

Tokyo 112-0012, Japanb Yokohama National University, Japan

Received 8 May 2000; received in revised form 27 September 2001; accepted 3 November 2001

Abstract

This paper is a proposal for business simulation compiler. This compiler can utilize

and modify a business simulation on the WWW easily for any person who is inexpe-

rienced in program development. This compiler was created as part of our business

simulation course. The course we are developing consists of: (i) a simple gaming ex-

periment among multiple students using Alexander Islands, a tiny business simulation

on the WWW; (ii) lectures to let students understand the core concepts of systems

management through the simulation; and (iii) the development of a homemade simu-

lation model by the students themselves using business model description language

(BMDL) and a business model development system (BMDS). Our course is unique in

the sense that, through the business simulation, we aim to develop students’ skills: (1) to

implement their own specific models of business firms, (2) to develop information sys-

tems for the firms, and (3) to understand business processes among companies. This

paper describes the background and motivation, basic principles, the architecture and

implementation of BMDL/BMDS, and the results of the experiments. � 2002 Pub-

lished by Elsevier Science Inc.

Information Sciences 143 (2002) 99–114www.elsevier.com/locate/ins

*Corresponding author. Tel.: +81-3-3942-6877; fax: +81-3-3942-6829.

E-mail address: [email protected] (K. Tsuda).

0020-0255/02/$ - see front matter � 2002 Published by Elsevier Science Inc.

PII: S0020 -0255 (02 )00194 -9

1. Introduction

This paper is a proposal for business simulation compiler. This compiler wascreated as part of a novel approach to a business simulation course at thegraduate school of systems management (GSSM) of Tsukuba University. Thegoals of the course are to develop students’ skills: (1) to implement their ownspecific models of business firms, (2) to develop information systems for thefirms, and (3) to understand business processes among companies.In order to achieve the goals, the most unique point of the course is to let the

students develop their own business simulations. The developed simulations arerunand evaluatedbyothermembers of the class, aswell as lecturers on theWWWenvironment. Through the experience, the students will eventually understandthe concepts and skills of business management. In order to develop a businesssimulation, advanced knowledge about computers or program development isrequired. However, few people have such experience in program development orcomputers. So, it is necessary to create a compiler that anyone could easily de-velop a business simulation with. This compiler consists of business model de-scription language (BMDL) and business model development system (BMDS).This paper describes the background and motivation, basic principles, the

architecture and implementation of BMDL/BMDS, some results of ourschool’s three years of course experience, and future issues.

2. Background and motivation

A business simulation is a common vehicle to study business and manage-ment principles under controlled virtual situations. The conventional approachto business simulation courses is, at least in Japan, to educate students on theconcepts of management, accounting, business processes, and/or the basictechniques for business analysis [5,10]. Then such education is applied on thenumerous conventional gaming simulations available in the literature in orderto attain these goals [2,11,13].However, at GSSM, such approaches are not enough. The students we have

are all business people from various industries. They have their own jobsduring the daytime, different expertise, and different backgrounds in their ex-perience. Therefore, although the academic levels of the students are so di-vergent, only playing simulations will not satisfy them. They want to knowhow to make good management decisions by the use and development ofbusiness models, decision support tools, and business information systems [8].To meet the requirements and based on our previous experience [3,4,14–16],

we set the following goals in designing our business simulation course:1. The game we will use is simple enough for business people of varying back-grounds, especially for those who have little accounting knowledge, thatthey can understand the basic process of business simulations.

100 K. Tsuda et al. / Information Sciences 143 (2002) 99–114

2. However, it is complex enough for those who have real and practical busi-ness experience to play the simulation in order to understand the advancedconcepts of decision-making and business processes.

3. Using the simulations, they will be highly motivated to further study ad-vanced courses at GSSM including operations research, information sys-tems, decision theory, accounting, marketing, computer programming,artificial intelligence, and/or computer networks.

4. Dozens of students can execute the simulations at the same time and fromdifferent locations, therefore, it is desirable that the simulation will run on acomputer network or on the World Wide Web.

5. To let the students easily develop their own business models, a new BMDLand BMDS should be designed and implemented. BMDL should be simpleenough that the students with limited skills on computer programming canunderstand it and write their own models.

6. To guide the students, a typical business model and simulation should bedeveloped. The simulation should be both executable as the introductorytool for the course and readable for students to understand how the modelis built, and how the simulation is executed. The simulation should be usedas an example in the introductory course.Based on the above, as a result, the course we are developing consists of: (i) a

simple gaming experiment among multiple students using Alexander Islands, atiny business simulation on the WWW; (ii) lectures to let students understandthe core concepts of systems management through the simulation [9,18]; and(iii) the development of a homemade simulation model by the students them-selves using BMDL and BMDS.

3. Framework of Alexander islands: a tiny business simulation

Alexander Islands is an introductory gaming simulation developed tomeet items 1, 2, and 6 of the requirements [7]. The simulation models abusiness process of (1) purchasing consumer items (e.g., personal comput-ers) from the headquarters, (2) selling them in two different markets(Herbert Island and Simon Island) and (3) among 10 competitors or 10players, making marketing decisions on ordering, advertising, pricing, andaccounting.The business model of Alexander Islands is summarized in Fig. 1. At every

turn (monthly) of the game, each user can order any amount of a sales itemfrom headquarters, prepare advertisements for radio and/or newspapers, de-termine sales pricing for the two markets, make accounting decisions on bor-rowing money and/or repaying loans. The demands of the two markets aredriven by the economic and social factors of those markets.

K. Tsuda et al. / Information Sciences 143 (2002) 99–114 101

The model implicitly includes a stock management problem in operationsresearch, demand forecasting in decision making, and advertising strategy inmarketing. Although the simulation does not include explicit decision supportfunctions [6], it is desirable for the students to be aware of the existence of suchpractical problems in the simple gaming environment. Therefore, to properlymake the decisions during the game, the players should have some decision aidson a PC, for example, a spreadsheet program. The simplicity of the simulationallows novice users to make decisions within 10 min; thus, the time to completeone game round is about 70 min. It is short enough for students that have theirown businesses.Alexander Islands consists of basic mechanisms of the business process and

user interfaces for 10 players and one manager. The user interfaces run on aweb browser. The first version of the simulation was implemented in C pro-gramming language, and re-implemented in BMDL in 1997. The source codeof Alexander Islands currently consists of about 450 steps of BMDL instruc-tions including detailed comments. The length is short enough that the studentscan read the contents and understand how it works.

4. Composition of a compiler

4.1. Framework of BMDL/BMDS

This section describes the architecture of BMDL and the BMDS. BMDL/BMDS was designed to meet items 3, 4, and 5 of the requirements in Section 2.Fig. 2 shows the system configuration.

Fig. 1. Business model of Alexander islands.


A model developer describes his or her business model in BMDL. A samplecode of BMDL is shown in Fig. 3. The example in Fig. 3 is a simulation de-signed for three players and one manager with 10 game rounds. The game isexecuted as follows: At the beginning, each player inputs the sales price; thenthe cheaper the price is, the more goods he or she can sell; all ordered goods aresold during every round; and a decision is made in order to supply new goodsto maintain the same stock levels.There are two interfaces; one for players to give a price and another for

managers. The managers interface is able to browse the players giving details ofthe player description and status. In the original code, the variables of themodel were described in Japanese or English. The mechanism enables the userto easily develop homemade simulations.The BMDL translator first translates a business simulation written in

BMDL into corresponding CGI scripts and C programs. The programs arethen run on a host computer with a WWW server and the model variable datain the form of spreadsheets. Finally, players execute the simulation throughbrowsers on the WWW environment. Model variables are managed in a modeldatabase with the configuration shown in Fig. 4.Simulation is executed with the architecture as shown in Fig. 5. Game

managers have the task of; controlling the input of information, availability,simulation calculations, simulation rounds, public opinion, team, and analysisdata. The other game players can input and modify the input variables basedon public and team-specific information and their own decisions. Fig. 6 showsa sample of the manager’s interface. Fig. 7 shows a sample of players’ inputscreen.

Fig. 2. Architecture of the business model development system.


Fig. 3. Sample code of business model description language.


4.2. Language specification of BDML

This section describes the details of BMDL. A sample code is shown in Fig. 3in the previous section. A file name of BMDL program sets an extension to‘‘.gg’’. In order to compile a program, it needs to be run through the compilerby running the command ‘‘gg5’’ and the file name. This is specified by theargument; ‘‘gg5 file-name.gg’’.BMDL consists of the following set of 17 commands. The details of a

command are explained with each command.1. ‘‘Def’’ CommandThe value, which specifies game composition, is set up.

Fig. 4. Memory management of business model development system.

Fig. 5. Functions of manager and players of BMDS/BMDL simulation.


Fig.6.Samplewindowofsimulationentry.


Fig.7.Sampleofsimulationdisplayforamanager.


def game� name game-namedef max� team number of maximum teamsdef max� round number of maximum roundsThese values must be set up.

2. ‘‘Password’’ CommandA password is set up.password controller-password team1-password team2-password . . .The next word of a command is a controller password. A subsequent wordbecomes the password of a team 1,2,. . .

3. ‘‘scon’’ CommandA series constant is defined.scon variable-name value_0 value_1 value_2 . . .The series of value are set up with defining series constant name.It becomes the value of the 0th round, the 1st round, . . . at order.

4. ‘‘gcon’’ CommandA global constant is defined.gcon variable-name valueThe value is set up with defining a global constant.

5. ‘‘ipage’’ CommandThe start of the input page is specified.ipage file-name link-nameHTML description

The file-name serves as the file name of the HTML description.The link-name is used for a link from an entrance page.HTML description is inserted in the head portion of a page.

6. ‘‘ivar’’ commandAn input variable and input classification are defined.ivar variable-name range minimum maximum [Default]ivar variable-name selectdefault-numerical-namenumerical-value-name . . .‘‘ivar - range’’ command creates the input column which a character can beinputted to freely between the maximum value and the minimum value.When a default is written, that value is indicated as an initial value inthe input column.‘‘iver - select’’ command creates a selection menu on the screen, and canchoose one now out of the inside. When a default is written, that valueis indicated as an initial value in the input column.

7. ‘‘ipre’’ commandThe value before 0 term of the ivar variable is initialized.ipre variable-name initial-valueSince a player inputs after 1 time, value cannot be set up.

8. ‘‘tvar’’ CommandA team variable is defined.tvar variable-name initial-value


When an initial value is specified, it becomes the value of the variable in around 0.After round 1, an initial value can not be specified because it is looked forby the calculation.

9. ‘‘tlet’’ CommandVariable calculation of each team is performed.tlet arithmetic expression‘‘arithmetic expression’’ described by the same format as C programminglanguage.The value of ‘‘one term ago’’, ‘‘two terms ago’’, . . . can be referred to byputting ‘‘@1’’, ‘‘@2’’, . . . after the variable name. Moreover, it is also pos-sible to call the mathematics function of the C language such as: sin(x),cos(x), log(x), log10(x), exp(x), pow(x, y), sqrt(x) and so on.

10. ‘‘prop’’ CommandThe proportional distribution to each team is calculated.prop team-variable-name¼ expression1 by expression2;The value of expression2 is calculated for every team and the distribution ra-tio for every team is calculated. The result that the value of expression1 wasdivided by the distributive ratio is substituted for the team variable name.

11. ‘‘pinv’’ CommandThe proportional distribution to each team is calculated.pinv team-variable-name¼ expression1 by expression2;The inverse number of the value of expression2 is calculated for every teamand the distribution ratio for every team is calculated. The result that thevalue of expression1 was divided by the distributive ratio is substituted forthe team variable name.

12. ‘‘dist’’ commandThe distribution based on the priority to each team is calculated.dist team-variable-name¼ expression1 by expression2 limit expression3The number of value of expression1 is distributed to the large order of ex-pression2. However, the amount of the maximum distribution of each teamis the value of expression3.

13. ‘‘ooption’’ CommandVariety about the output is specified.ooption form-specificationA is the same form as the form specification for the double accuracy realnumber types of ‘‘printf’’ of the C programming language such as‘‘%5.3lf : A minimum of 5 figures, below a small number of point 3 figure.3.141, 0.234, etc.’’

14. ‘‘opage’’ CommandThe start of the output page is specified.opage file-name Link-name ½publicjteamspecjcontrol�HTML � description


The file-name serves as the file name of the HTML description. The link-name is used for a link from an entrance page. HTML description is in-serted in the head portion of a page. Options are as follows:

• public All teams can be referred to.• teamspec Only a self-team can be referred to. (A team password isrequired.)

• control Only a controller can be referred to.15. ‘‘begintable’’ Command

A start of the table in an output page is specified.begintableIt specifies that what is in-between from this command to ‘‘endtable ’’ com-mand becomes one table.

16. ‘‘endtable’’ CommandAn end of the table in an output page is specified.endtableHTML description

An end of the table is marked. HTML description can be placed next.17. ‘‘out’’ Command

The contents of a table are outputted. The ‘‘out’’ commands are describedbetween ‘‘begintable’’ and ‘‘endtable’’.out teamsout roundsout values form-specification . . .out teams-vars form-specification . . .out rounds-vars form-specification . . .The ‘‘out teams’’ command outputs a team number as a title.The ‘‘out rounds’’ command outputs a round number as a title.The ‘‘out values’’ command outputs each item of output specification toone line of a table. Form-specification is following.• String That string is indicated as it is.• - The cell serves as a blank.• Arithmetic expression The value of the arithmetic expression is indicated.The ‘‘out teams-vars’’ command and the ‘‘out rounds-vars’’ command in-dicates the item of the output specification of each team and each round inone line of a table.

5. Experience and discussion

5.1. Outline of the course experience

The course was started in 1996, when we had no specific environment to run,develop or operate a business simulation. In 1997, Alexander Islands using the


C programming language was used in the introductory simulation (sub-)course, and the BMDL version was introduced in the advanced course as ameans for the students to develop their own business models. The students didnot welcome the 1996 program because the supplementary tasks made it toodifficult to understand the business management principles.The 1997 program was so remarkably improved as the students could un-

derstand the model of Alexander Islands and could develop their own home-made simulations. Questionnaire data on the course was gathered. Amongst 23respondents of the questionnaire, (1) 22 students replied that the course usingAlexander Islands was interesting, (2) 17 students thought the level of thecourse was moderate, and (3) 18 students were comfortable in the WWW en-vironment.Summary of the models the students developed are shown in Table 1. They

cover a diversity of task domains in practical business situations, although ourBMDL/BMDS toolkit mainly fits the style of assembly type production andsales companies.

5.1.1. 1998 program plan and Tiny-P modelIn the 1998 program, we provided the students with one very simple business

model: Tiny-P, which runs on our environment in order to let students use it asa prototype or a sample source code for their own projects. The model wasoriginally designed to be used as a small case study of our course, whichsimulates a production firm. Although it is simple, it can be extended to meetthe students’ complex requirement.The specifications of Tiny-P are summarized in Table 2. The corresponding

source code in BMDL contains about 100 lines of code including comments onthe case.

5.2. Evaluation

In the 1998 program, we think we attained most of the design goals de-scribed in Section 2. From the questionnaire data among 15 respondents, wereceived the following comments:

Table 1

Homemade simulations developed in the 1997 program

1. Model of production line improvement via research and development decision making

2. Model of equipment replacement for production line improvement

3. Model of resource purchasing for production company

4. Model of research and development investment for new products

5. Model of model changes of products

6. Placement of logistic bases

7. BS/PL/Cash flow model


1. All of the students replied that the course with Alexander Islands wasinteresting and that they would recommend the course to others;

2. 11 students thought the level of the course was moderate, and3. most of the students requested more intensive lectures and discussionsamong students.The plan of developing homemade simulations in 1999 includes the candi-

dates in Table 3.From these observations, we believe that our novel course is of success for

those students with various background and expertise. The important impli-cation is that using the business simulation approach and the BMDL/BMDStoolkit, we can approach the business processes we would like to model andanalyze.

6. Conclusion and future work

This paper has described our experience in developing a novel course onbusiness simulation. Unlike conventional gaming simulation courses, whichaim at studying basic principles of simulated business processes, accounting or

Table 3

Project candidates for simulation development in the 1998 program

1. Marketing competition model

2. Model of production industries

3. Model of accounting systems

4. Model of finance systems

5. Model of players of business simulations

6. Scenario making for business simulations

Table 2

Specifications of Tiny-P model

1. Kind of products: Only one product A

2. Kind of material parts: Only one part a

3. Decision variables:

Sales view: One: Price of product A

Production view: Two: Number of product A

Number of order a

4. How to order parts:

Parts price: Constant

Number of parts: Provided the number exactly required

Lead time: One term

5. How to make a product:

The product consists of 50 parts lead time: One term


data analyses techniques, the objectives of our course are to develop skills: (1)to implement the students own specific models of business firms, (2) to developinformation systems for the firms, and (3) to understand the business processesamong companies.To attain the objective, the most remarkable point is that the course

contains: (1) Alexander Islands, a tiny business simulation on the WWW, and(2) The development of homemade models via BMDL and BMDS. The ap-proach is promising for business simulation courses as it challenges the cre-ators of the course as well as the students to develop more advanced systemsand concepts.Future work includes: (1) an improvement of the functions of BMDL/

BMDS by providing agent-based technology [1,2,12,17] in (Distributed) Arti-ficial Intelligence, which will enable the user to execute multi-player simula-tions although (human) users are not multiple, and (2) the development ofcorresponding textbooks to guide the courses.

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a compiler for business simulations: toward business model development by yourselves

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