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Int. J. Production Economics 112 (2008) 630–645

www.elsevier.com/locate/ijpe

Development of an RFID-based sushi management system:The case of a conveyor-belt sushi restaurant

E.W.T. Ngai, F.F.C. Suk�, S.Y.Y. Lo

Department of Management and Marketing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong

Received 28 February 2006; accepted 2 February 2007

Available online 16 June 2007

Abstract

We describe the design and development of a radio-frequency identification (RFID)-based sushi management (RFSM)

system in a conveyor-belt sushi restaurant to enhance operational efficiency. The system is designed to help a conveyor-belt

sushi restaurant to achieve better inventory control, responsive replenishment, and food safety control, as well as to

improve its quality of service. This study demonstrates the significance and benefits of using RFID technology specifically

in the food industry. The lessons learned from this effort help to support and further the academic and practitioner

literature, especially in the area of RFID systems development. Finally, we address the limitations of this study and several

areas of future development.

r 2007 Elsevier B.V. All rights reserved.

Keywords: Radio-frequency identification (RFID); Sushi management system; Food safety; Food industry

1. Introduction

Radio-frequency identification (RFID) techno-logy has been widely used in many industries,including the airline industry (Wyld et al., 2005;O’Connor, 2006), cattle industry (Mennecke andTownsend, 2005), construction (Jaseiskis andEi-Misalami, 2003; Song et al., 2006), logistics(Ngai et al., 2007), healthcare (Collins, 2005), andmanufacturing (Swedberg, 2006). In this study, wefocus on the use of RFID in the food industry. Weillustrate the significance and benefits of an RFID-based sushi management (RFSM) system in a

e front matter r 2007 Elsevier B.V. All rights reserved

e.2007.05.011

ng author. Tel.: +852 3400 3584;

0611.

ss: msfred@inet.polyu.edu.hk (F.F.C. Suk).

conveyor-belt sushi restaurant to enhance opera-tional efficiency and food safety.

Diners are conscious of food safety, as are foodoperators. Poor food management can result in ahigher potential for parasitic or bacterial contami-nants to develop, or even for food poisoning tooccur. Food safety monitoring and control isparticularly crucial for a Japanese cuisine like sushi.Sushi is a food made from vinegared rice combinedwith various toppings or fillings such as seafood,vegetables, mushrooms, eggs, and meat. This kindof food is renowned for its fresh taste; eating it rawis common. If sushi with raw toppings is exposed fortoo long at room temperature, its food content islikely to become contaminated and its qualityimpaired. It is important for sushi restaurants tohave an effective food control process to assure thatthe sushi is safe for consumption. Thus, in this

.

ARTICLE IN PRESSE.W.T. Ngai et al. / Int. J. Production Economics 112 (2008) 630–645 631

paper, we make use of the RFID technology withthe aim of examining ways to strengthen food safetycontrol in the food industry, particularly in sushirestaurants. In addition, we demonstrate the use ofRFID technology to improve inventory control andresponsive replenishment in the industry.

In a sushi restaurant, the display of sushi on aconveyor belt is becoming more popular. The sushirestaurant features an elliptical counter aroundwhich diners can sit and take the food. A conveyorbelt revolves around the perimeter of the counter,displaying a colourful variety of sushi, usually twoor three pieces per plate. As the sushi plates pass by,diners simply reach out and select their favourites.This provides a cheap and convenient way ofeating sushi. However, traditional conveyor-beltsushi restaurants are facing several operational andmanagement challenges:

(i)

They are time-consuming and there is a potential

for human error in billing

Traditionally, sushi restaurants have been usedto adopting a plate-colour pricing scheme. Inthis scheme, the price category of a variety ofsushi food is signified and coded with plates ofdiffering colours. When diners finish theirmeals, their bills are calculated according tothe price category of each plate colour multi-plied by the number of plates of each colourthey have taken. This kind of billing calculationis done manually. It is a time-consumingprocess and human errors sometimes occur intotalling the bills, causing a loss to either adiner or to the restaurant.

(ii)

There is a potential food hazard

Freshness is an important food quality forsushi. To preserve this quality, each sushi itemshould be stamped with a label to indicate thetime when it was prepared. After the expirydate, sushi is supposed to be not suitable foreating because it might be bacterially contami-nated and subsequently pose health risks to adiner. A sushi chef is thus used to removing theexpired food from the rotating belt regularlyand manually. However, it is not easy for thechef to identify and monitor the expired sushion the conveyor belt.

(iii)

Sushi stock control on the belt can be ineffective

A typical sushi restaurant normally offers morethan 30 kinds of sushi on its menu. Diners mayfrequently not be able to find all kinds of sushion the conveyor belt. Though diners might

attempt to specially order a particular type ofsushi, they may sometimes be told that the itemis out of stock or sold out. This not onlyfrustrates the appetite of diners, but alsoimpacts on the quality of service. Sushiinventory monitoring and control on the beltis crucial to attract new and repeat diners. Bothunderstocking and overstocking have implica-tions for the efficiency of the inventory manage-ment. Currently, it seems that no system isavailable to effectively manage the sushi stockinventory on the belt. In addition, it is hard forsushi restaurants to analyse and identify thepopularity of the sushi sold. The currentpractice of sushi restaurants for learning aboutthe popularity of sushi items is based on thechef’s experience or perceptions. The datavisibility of the stock inventory is poor.

From these operational and management chal-lenges, research questions arise. Can informationtechnology be used to help manage the challenges?What are the benefits of using information technol-ogy? How can the billing process be streamlined andits efficiency and accuracy enhanced? Can theremoval of the expired food be done precisely andautomatically, in order to strengthen food safety?How can the food inventory control be improved inorder to achieve a more responsive replenishment?With these questions in mind, we propose usingRFID technology as a solution for a conveyor-beltsushi restaurant.

Sushi food is well known and popular worldwide,not only in Japan. Many sushi restaurants areoperating in the US, Europe, and Asian countries.The market size of sushi restaurants has been growingrapidly in most Asian countries. RFID technologycan be effectively applied in sushi restaurants to helpimprove their food safety, inventory control, servicequality, operational efficiency, and data visibility. Thepurpose of this study was to examine how theadoption of RFID technology could help to improvethe operational efficiency of a conveyor-belt sushirestaurant. We develop a framework and present acase study to illustrate an RFSM system for a sushirestaurant. Specifically, the objectives of building theproposed system were to:

�

simplify the billing process by using a personaldigital assistant (PDA) device for counting foodplates and calculating the billing amount toenhance billing efficiency and accuracy;

ARTICLE IN PRESSE.W.T. Ngai et al. / Int. J. Production Economics 112 (2008) 630–645632

�

provide tracking information about food on thebelt to enable the more effective removal of theexpired items in order to strengthen the controlof food safety; � improve the food inventory control on the belt by

responsive replenishment; and

� provide visible operations statistics for inventory

management and marketing promotion.

The rest of the paper is organized as follows. InSection 2, we present a brief overview of previousRFID applications. Then in Section 3, we describeour proposed framework of an RFSM system.Following this, we address the limitations of thesystem and propose future improvement work.Finally, a conclusion is drawn.

2. Previous RFID applications in the food industry

Kumar and Budin (2006) indicated that the USFood and Drug Administration reported a total of1307 processed food product recalls between 1999and 2003. In Japan, a massive recall was alsoreported from two Japanese food makers in 2002(Jiji Press, 2003). Demand for higher food hygieneand safety is becoming a growing concern (Kerryet al., 2006).

RFID technology has already been adopted foruse in the food supply chain and to improve thetraceability of food (Hutter, 2004). In food supplychain management, a food operator can use RFIDtechnology to record and provide information on allstages from supplier, transportation, and produc-tion, to storage and distribution of an individualfood item. Food traceability refers to the ability totrace and follow a food, feed, food-producinganimal, or ingredients, throughout the productionand distribution process (Regattieri et al., 2007).With effect from January 2005, the European FoodLaw requires food operators to identify theirsuppliers and customers, and to provide thisinformation to the authorities concerned (EEC,2002). Use of RFID technology has been reportedto be a solution to enable such tracing capability inthe supply chain of the food industry (Kumar andBudin, 2006; McMeekin et al., 2006). The RFIDtags attached to individual food products allowsuppliers to trace every movement of their foodproducts throughout the production, storage, trans-portation, and point-of-sales processes. Karkkainen(2003) conducted a trial of the use of RFID taggingfor short-shelf-life goods in 1998, demonstrating

that the adoption of RFID technology can achievethe benefits of improving replenishment productiv-ity and reducing stock loss in the supply chain ofshort-shelf-life products. Jones et al. (2005) reportedthat RFID technology can offer a wide range ofbenefits to food retailing in the UK throughout thesupply chain, including tighter management andcontrol of the supply chain, reductions in shrinkage,reduced labour costs, and improved customerservice, facilitating compliance with traceabilityprotocols and food safety regulations. Kumar andBudin (2006) also concluded that RFID plays apivotal role in the prevention of food productrecalls.

Specifically, for the meat-processing industry,Mousavi et al. (2002) proposed a solution usingRFID technology to track meat products andprovide information about them which is attachedto them throughout the production process untilthey become retail packs. They indicated that RFIDtechnology offers a number of potential benefits tothe meat production, distribution, and retail chain,including improving food quality control, safety,traceability, inventory management, and labour-saving costs. In addition, in the agricultural foodindustry, Thysen (2000) indicated that IT hadbecome important to the industry as a means ofachieving better food control and safety, as well ashigher precision in the use of chemicals and in thecare of farm animals. Wang et al. (2006) presentedan overview of the development of wireless sensortechnologies and standards for wireless communica-tions in agriculture and the food industry. Thesekinds of wireless sensor technologies are used forenvironmental monitoring, precision agriculture,M2M-based machines and process control, buildingand facility automation, and RFID-based trace-ability. They predicted that, given the advantages ofRFID technology over the traditional barcodemethod, the development and deployment of RFIDin food traceability would increase significantly inthe near future. In addition, Jedermann et al. (2006)proposed a system using a combination of RFID,sensor networks, and software agents to trace fruittransports, demonstrating an effective use of RFIDtechnology in fruit logistics.

In the early phase of RFID technology, itslimitations related to its high cost and the unlikeli-hood of a pay-off of the investment (Burnell, 1999;Riso, 2001). However, according to Jones et al.(2005), the price of an RFID tag was about $1 in2000, had fallen to $0.25–0.35 by early 2004, and is

ARTICLE IN PRESSE.W.T. Ngai et al. / Int. J. Production Economics 112 (2008) 630–645 633

expected to drop to around $0.05 as RFIDtechnology becomes more widely adopted. Further-more, the capability of RFID technology has beencriticized as being too similar to that of the barcode.Burnell (1999) inferred that most of the function-ality needed had already been achieved by barcodetechnology. Karkkainen (2003) pointed out thelimitations of barcode data collection, includingthe occasional necessity to read barcodes manuallyand poor barcode readability in some environments.Despite the potential limitations perceived early onin the development of RFID technology, severalrecent studies have indicated that investing in RFIDtechnology is promising and an excellent long-termcapital investment (Karkkainen, 2003; Kumar andBudin, 2006; Regattieri et al., 2007).

3. Architectural framework of an RFSM system

In this section, we demonstrate the architecturalframework of an RFSM system. First, we give anarchitectural overview of the system in terms of fivecross-sectional layers of the system presented. Then,we describe six stages in the design and developmentof the proposed system, including the businessprocess analysis, the requirements analysis and the

SushiManagement

System

Track &TraceModule

Data Capturing an

ERP

Sushi Quality Manage

…………

RFID reawith antand tags

Readpoint 1

Readpoint 2

5. ApplicationLayer

4. Work-FlowLayer

3.ProcessingModules

2.DataCapturingLayer

1.Data CapturingFront-end

Fig. 1. Architecture of t

RF site survey, system architecture, system design,implementation, and testing and evaluation.

3.1. Architectural overview

We designed and developed an architecturalframework of an RFSM system using RFIDtechnology. Fig. 1 shows an overview of the archi-tectural framework of the system. It comprises fivelayers in total.

(i)

d Tra

ment

PO

derenna

DB

he RF

Data-capturing front-end system

The first layer is a data-capturing front-endsystem. It has three components: a transponder,a reader, and an antenna. The transponderconsists of RFID tags located on the sushiplates. Each tag contains information about thesushi, such as its price, type, date and time ofproduction, calories, and so on. A reader isequipped with an antenna and is used to read orwrite information onto the RFID tag. Whenthe sushi plates are on the belt and pass by thereaders, tag information is retrieved to deter-mine the freshness of the food items. Thecurrent time is compared with the sushiproduction time stored in the tag. If the time

Data Monitoring andAlerting Module

nsformation Framework

(SQM) Work-Flow Engine

…S OtherApplications

Readpointx

Readpointy

RFIDHandheldReaderand Tags

DB

SM system.

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difference is greater than a specified interval,the sushi is regarded as having passed its sell-bytime, and will then be removed automatically.In addition, during the process of billing thediner, an RFID hand-held reader is used toconduct a quick scan of his or her plates ofsushi. A small portable printer can be attachedto the device for receipt printing.

(ii)

Data-capturing and filtering layer

This is a middleware system that assists with thefiltering, aggregation, and routing of RFIDdata. The data include the timestamp, and thereader and antenna identity.

(iii)

Processing modules

The captured data are classified and stored ondatabases which are specifically responsible forstoring the billing information, and monitoringand controlling the freshness of the sushi,respectively. Some of the captured data areused to directly drive the workflow engines inthe back-office systems. A sushi quality-man-agement workflow engine is developed in thesystem.

(iv)

Workflow layer

Workflow functionality is located at Layer 4which is used to coordinate, manage, andintegrate the processes and data flows withinthe new sushi management system and theexisting system applications like ERP and POS.The middleware has built-in business rules,which are specified in an ‘‘if–then’’ format. Itallows the rule engine to reason about the flowof information above and below this layer. Forinstance, a business rule for monitoring theexpiry time of sushi looks like ‘‘if a sushi dish isdue to reach its expiry time in 1min, then analert will be issued to the chef’s computer andthe sushi will be displayed in red on the chef’scomputer screen’’. According to the needs ofthe chef, this rule can be changed by adjustingthe time at which the alert regarding the expirytime is issued.

(v)

Applications layer

Above the workflow layer, there is an API layerwhich provides the necessary application inter-faces for data exchange between new andexisting applications. User applications are inthe upper application layer which provides thegraphical user interfaces for the users to use theapplications; that is, an enterprise resourceplanning (ERP) system, point-of-sales systems,and so on.

3.2. Architectural framework design and

development

We used a six-stage structural developmentmethod to design and develop the architecturalframework of the RFSM system: (1) businessprocess analysis, (2) requirement analysis, (3)system architecture, (4) system design, (5) systemimplementation, and (6) system testing and evalua-tion. We describe each stage below.

3.2.1. Stage 1: business process analysis

A business process refers to the way a particularbusiness is conducted. It relates to the businessrules, strategies, and unique ways in which anorganization coordinates work, information, andknowledge, as well as to how management coordi-nates work (Laudon and Laudon, 1998). RFID isan emerging and innovative technology. RFID canbe an enabler in effecting changes and achievingproductivity gains using techniques that re-engineerthe business process. It can help to fundamentallyredesign the business processes of sushi restaurantsin order to optimize their benefits and theiroperational efficiency. As there is little knownliterature on the operations and managementof a conveyor-belt sushi restaurant, we have ado-pted various approaches to acquire the business-process knowledge of sushi restaurants. Herbst andKaragiannis (2000) indicated that business-processknowledge could typically be acquired by conduct-ing interviews or by using a questionnaire survey.We therefore conducted interviews with staffworking in a restaurant, with the aim of observingtheir operations at the same time. In this study, wevisited three sushi restaurants and interviewed 10staff holding a variety of positions, ranging frommanager, chef, waiter, and stock-taker to cashier.These interviews not only enabled us to understandthe current processes, operations environment,and weaknesses at the managerial level, but alsoprovided significant insights into the weak areas atthe operational levels.

In the typical flow of a conveyor-belt sushirestaurant, a stock-taker makes orders of rawmaterials from various suppliers by phone or fax.Non-systematic stock taking and distribution of thematerials to the restaurant floor are observed. Thesushi chefs make the new sushi based on their roughestimation of the number of food items stillcurrently available on the belt. After preparing thenew sushi, they place it on plates of the colour

ARTICLE IN PRESS

Table 1

Stakeholders’ requirements

Stakeholders Requirements for RFSM

Customer/

diner

� To provide a visual view of an entire

conveyor belt in the shop which allows

diners to know the types of sushi available

on the belt, their prices, calories, etc.

� To be effective and accurate in the billing

procedure

Shop

manager

� To maintain staff records

� Maintain sushi menu records

� Report different kinds of sushi consumed

and available quantity

� Provide sales and inventory reports

Stock-keeper � Record the inventory in and out situations

� Provide a reminder for responsive

replenishment

� Maintain supplier records

Chef � Update sushi information onto RFID tag

embedded on the plates

� Provide a reminder and alert of the expired

sushi on the belt

� Remove the expired sushi automatically

� View the quantity of different kinds of sushi

on the belt

Waiter � Simplify the billing procedure

� Provide an automatic tool for bill

calculation

Cashier � Streamline the bill payment process

E.W.T. Ngai et al. / Int. J. Production Economics 112 (2008) 630–645 635

appropriate to its price and give it a paper label toidentify it. The new sushi is then placed onto theconveyor belt and is ready for eating. Havingfinished their meals, the customers call for a waiterto manually count the number of coloured platesand calculate their bills. Normally, a cashiercalculates and audits all the billing items to confirmthe diner’s bill. After our process analysis, weidentified a number of core business processes thatcould be redesigned, in particular, the replenishmentprocess, sushi-tracking process, and billing process.We describe how to improve the efficiency of theseprocesses in the requirement analysis stage.

3.2.2. Stage 2: requirements analysis and RF site

survey

Having acquired the business process knowledgeand understood the operational environments ofsushi restaurants, we began to analyze their businessneeds and redesign business processes. In addition,we conducted an RF site survey to help to preparethe facilities for the deployment of an RFID system,including pilot testing of RFID tags, readers, andthe antenna. To predict the site performance of ourRFID solution, we studied and analyzed potentialinterferences in the restaurant environments likewireless networks, short-range radios, and mobilephones.

Having had discussions with the stakeholdersconcerned, we analyzed and summarized their keyfunctional requirements for an RFSM system; theseare shown in Table 1.

After analysis of the business requirements of thestakeholders, an RFID-based conveyor-belt sushisystem was proposed. The stock-taker could placean order of raw materials from the suppliers via thesystem. It simplified and shortened the time requiredfor the replenishment process. The stock-keepercould also use the system to systematically recordorder information from the suppliers and monitorthe available stocks in the shop floor and therefrigerator. The restaurant manager could use thesystem to view statistics of the current inventory,sales records, staff information, and so on. Thechefs could replenish and prepare the right quan-tities of different kinds of sushi in the light of thequantity already available on the belt as shown onthe display screen of the system. In addition, thesystem provided a reminder and alert to the chefsand helped to automatically remove those fooditems that had reached their expiry time from thebelt. Diners could see which sushi dishes were

available on the belt from the display screen so thatthey were able to tell if their delicacies were on thebelt, instead of having to keep mental track of thesushi dishes available on the belt. After they hadfinished their meals, a waiter could bring a PDAdevice to them to perform a quick scan of thenumber of coloured plates, in order to make outtheir bills. A receipt with the transaction number,sushi names, and their prices and quantitiesconsumed could be printed out. A cashier couldsimply input the transaction number for thepurposes of settlement of the bill, without beingrequired to re-calculate all the items on it.

3.2.3. Stage 3: system architecture

In this stage, we performed an architectural deve-lopment of the system. According to Nunamaker

ARTICLE IN PRESSE.W.T. Ngai et al. / Int. J. Production Economics 112 (2008) 630–645636

et al. (1990), a system architecture provides a roadmap for the system-building process by placingcomponents into perspective, defining their func-tionalities, and demonstrating how they will interactwith one another. It is an initial process in thesystem development process. We firstly identifiedthe subsystems and established a framework forsubsystem control and communication. Then, wedefined the functionalities of each component anddescribed the operations and communication inter-faces between one component and another.

A system overview is shown in Fig. 2. It depictsan RFSM system consisting of five key components:(i) user interface, (ii) database server, (iii) LCDscreen display, (iv) plates embedded with an RFIDtag, and (v) the RFID reader. All of them are linkedup with the Intranet or Internet through a wired orwireless network.

We describe each of the key components below.

(i)

R

em

su

User interface: Computers that could access theIntranet were provided to various stakeholders:one computer each was prepared for themanager, the cashier, the stock-keeper, and

Sushi Maker

Sushi Information Display

Update Sushi Information

Small portableprinter

Billing

Staff

Stock KeeperInventory Control

Wireless Network

Database

RFID Reader

FID Reader

RFID

RFID

bedded

shi plate

RFID

embedded

sushi plate

Fig. 2. Overall architecture of th

the chef, and two were for controlling theLCD display screen. A portal PDA equippedwith an RFID reader and a small portableprinter was provided to waiters via a wirelessnetwork.

(ii)

Database server: The database server consistedof various specific databases like HR, sushiinformation, inventory control, supplier infor-mation, transaction management, and RFIDinformation. The databases were accessedthrough the open database connectivity (ODBC)gateway to execute a query.

(iii)

LCD screen display: LCD screens were locatedin the front area of a restaurant to allow dinersto know what types of sushi were available onthe belt. LCD screens were also placed facingthe chefs so that they could see the quantitiesavailable on the belt and decide on the supplyof new food items.

(iv)

Plates embedded with RFID tag: A tiny RFIDtag was embedded into plates carrying sushi.The tag information could be either read orwritten to by an RFID reader in order toretrieve and update the food information.

Conveyor Belt

Conveyor BeltInformation Display

Display System

Transaction

Administration

Manager

Cashier

Server

CustomerReader

e RFSM system.

ARTICLE IN PRESSE.W.T. Ngai et al. / Int. J. Production Economics 112 (2008) 630–645 637

(v)

C

Wa

RFID reader: RFID readers were placed atfixed positions on the conveyor belt to examinethe availability and freshness of the sushi.Another RFID reader was also located on thetable for chefs to update the tag informationon the sushi-carrying plate. An RFID readerwas attached to the portal PDA for billingpurposes.

We further determined the hardware and soft-ware requirements of the system. The recommendedquantity and processing power of the requiredequipment depended on the size of the sushirestaurant. In general, the system was composedof the following components:

Hardware requirements

�

RFID tag � RFID reader � Web and application server � Database server � LCD screen � PDA

Wireless and Ethernet network

�

Software requirements � Apache web server

ashier

iter/Waitress

Generate the receipt TransactionDatabase

HR Datab

Menu Management

Maintain Staff Record

Sushi Data

Manager

Statistical RecordInvento

Stock-Keeper

Transaction

Fig. 3. Use case diagram o

�

ase

bas

ry D

f th

Tomcat application server

� RDBMS database � Browser with Flash Player

3.2.4. Stage 4: system design

System design is an important aspect of systemdevelopment. It involves an understanding of thedomain being studied, the application of variousalternatives, and the synthesis and evaluation of aproposed solution (Nunamaker et al., 1990). In thisstage, a systematic and high-level system design andanalysis of the prototype system was performed.The design of the entire system followed a three-tierstructure, namely the client–server–server model. Insuch a system, the first tier is the thin client browser,through which users can access applications via webservices. In the middle tier, user requests arevalidated, controlled, and redirected for furtherprocessing. The final tier encompasses the relevantbusiness components where user transactionsare processed and stored. We divided the systeminto subsystems and components based on func-tionality. A detailed subsystem design was con-ducted by means of a high-level modelling language.Typically, we used a Unified Modelling Language

e

Sushi MakerDisplay System

Maintain sushi production recordSushi-on-the-belt

Databaseatabase

Stock-in-and-out Record System

Supplier DatabaseMaintain supplier Information

Customer

e RFSM system.

ARTICLE IN PRESSE.W.T. Ngai et al. / Int. J. Production Economics 112 (2008) 630–645638

(UML) to model and walkthrough use cases of thesystem. The deliverables of this stage would act as ablueprint for the system implementation in the nextstage. Fig. 3 shows a case diagram of the proposedRFSM system.

We describe each of the subsystem functionalitiesbelow.

(i)

Human resources management subsystem

This subsystem enables a restaurant manager tomaintain staff record information, includingpersonal information, training arrangement,leave application, and performance and apprai-sal evaluation.

(ii)

Stock in-and-out record subsystem

This subsystem helps keep track of the inven-tory of all raw materials used in a restaurant. Itprovides a built-in ‘‘red–yellow–green trafficlight’’ signalling function to assist monitoringand control of the stock. The stock above thethreshold level is shown in green; yellowindicates that the stock on the shop floor isnearly used up, and that redistribution from therefrigerator is necessary. Red shows that thetotal stock of a particular raw material hasdropped below the threshold level and that anew order should be placed with the suppliers.Supplier information is stored in the system tofacilitate the placing of a new order via thesystem.

(iii)

Press-to-make subsystem

This subsystem enables chefs to update sushi-carrying plate tag information after makingnew sushi. Before the chefs put the plate on thebelt, its timestamp is updated via the system sothat effective tracking and monitoring of theexpired food can be achieved. In addition, stockinformation on the available sushi on the beltis updated and shown on the LCD displayscreen to let the diners know that new sushi isavailable on the belt.

(iv)

Billing subsystem

This subsystem helps a waiter to simplify thebilling process. The waiter carries a PDA devicewith an RFID reader and a small portableprinter. Using the PDA device, a quick scanof the coloured sushi plates is performed.A diner’s bill is then calculated automaticallyby the system. A receipt with the billingnumber, sushi names, and their prices andquantities consumed can be printed using theportable printer. In addition, the billing data

are sent through the wireless network to thesystem databases. A cashier can use the billingdata to accurately settle a diner’s bill.

3.2.5. Stage 5: system implementation

Implementing a system is an engineering concept(Scott-Morton, 1984). Prototyping is a quick way ofdemonstrating a solution to a problem. It also helpsto uncover any potential inherent problems. In thisimplementation stage, we developed the RFSMsystem according to our architectural and systemdesign. HTML, JSP and Javascript, and Macro-media Flash programming languages were selectedfor the development of web-based interfaces, as theywere portal and compatible with most web brow-sers. In addition, we used Java and Java servletsfor developing modules in the middle tier such assession tracking and flow redirecting, because mostof the current application servers like Tomcatwidely support these kinds of Java components.Finally, a structured query language (SQL) wasused for writing statements and queries in therational database management (RDBMS) system.The open database connectivity (ODBC) protocolwas selected to communicate between the databaseserver and the application server. Both SQL andODBC are compatible with a variety of RDBMSdatabases.

3.2.6. Stage 6: system testing and evaluation

Having developed the system prototype, we testedand evaluated it thoroughly in this phase to see if itworked correctly and met the requirements. Weperformed a set of formal tests on the system,including module testing, integration testing, func-tionality testing, and performance testing, to insurethe prototype was running free from bugs anderrors.

In addition, we further examined the prototypeby inviting domain experts to evaluate it. Gaschinget al. (1983) indicated that domain expert evaluationis effective to help determine the accuracy of theembedded knowledge in the prototype. We em-ployed a user questionnaire to document responsesto system testing. In order to obtain comprehensivefeedback, 43 university students studying for part-time degrees in hotel and catering management aswell as tourism management (most of them workedin food and catering-related industries in thedaytime) were invited to participate in the evalua-tion. At the evaluation session, the system prototypewas demonstrated and feedback was solicited from

ARTICLE IN PRESS

Table 2

RFID benefits and challenges

RFID benefits RFID challenges

Technological perspective

� Proven technology

adopted in food industry

� Responsive multiple tag

real-time read/write

capabilities

� Long read range without

specified sight requirement

� Normal functioning even

in a restaurant with

dimmed lighting or harsh

environment

� High implementation cost

� Incompatibility with

existing legacy systems

� Non-standardization of

RFID technology

Methodological perspective

Improving billing process as

well as its efficiency and

accuracy

Potential re-engineering and

impacts on a firm’s internal

business processes

Managerial perspective

� Strengthening food quality

and safety control

� Enabling responsive

replenishment

� Improving dining

experience and service

satisfaction

� Reducing out-of-stock

situations

� Insufficiency of strong

expertise in RFID

technology

� Resistance to

technological change

� Expenses for staff

retraining

Application perspective

� Tracking the availability

of sushi on the belt

� Providing useful food-

content information to

diners

� Inadequate in-depth

technical and application

supports

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the students through discussion. The results of theprototype evaluation were satisfactory and sup-ported the contention that the RFSM performed itsfunctions as expected. Five sushi chefs and man-agers were also invited to evaluate the prototypesystem. A formal questionnaire containing bothclosed and open-ended questions was designedwhich consisted of two sections: (i) effectiveness ofthe prototype system and (ii) usability of theprototype system. The potential users were askedto use a 5-point scale (1 ¼ strongly disagree,3 ¼ undecided, and 5 ¼ strongly agree) to rate thetwo main aspects of the prototype system: itseffectiveness and its usability. The results of thequestionnaire analysis show that the potential usersand sushi experts rated the system highly on theabove two aspects with a mean score of least 3.5 ona 5-point scale. Based on the results of theevaluation, the prototype is seen to be a promisingsystem for improving the operational efficiency of aconveyor-belt sushi restaurant. They were positiveabout the potential of the system, indicating inparticular that it was helpful in speeding up thecalculation of the bill and improving the qualitycontrol of the sushi.

4. RFID benefits and challenges: lessons from the

case study

The benefits and challenges of the developmentof the RFSM prototype system were examinedfrom different perspectives: technological, metho-dological, managerial, and applications. Some in-sights obtained from involvement in developingthe RFSM prototype system are summarized inTable 2. The benefits of the RFSM system in a sushirestaurant can be described as follows:

(i)

Keeping the stock records of the raw materials

for making sushi electronically

This provides greater visibility of the up-to-datestock information on the raw materials formaking sushi. This system enables a real-timeoverview of stock levels and reduces the possi-bility of becoming out-of-stock. Inventory accu-racy is important to help improve visibility andinsure the right materials are available, and tobetter manage the just-in-time production model.

(ii)

Tracking the real-time consumption and avail-

ability of sushi on the belt

Better visibility of the inventory and automateddata capture can remove the human factor in

track-and-trace operations with the sushi onthe conveyor belt. This allows the sushi chefs orthe manager to instantly query the real-timeconsumption and availability of food items onthe belt. Based on this information, the chefscan decide the quantity and type of sushi theyneed to make to insure sufficient supply of avariety of food on the belt.

(iii)

Enabling responsive replenishment

Information generated by the system can beanalyzed to enable demand forecasting of typesof sushi. It can assist chefs or managers toperform effective strategic planning in theirdaily operations.

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(iv)

Removing the expired sushi from the belt

automatically to strengthen food safety control

The traceability function of the timestamp onthe sushi dish can facilitate access to informa-tion concerning sushi’s freshness; that is, thelength of time each sushi item has been onthe conveyor belt. It can be assured that ex-pired food is automatically removed by thesystem and food safety control can thus bestrengthened.

(v)

Simplifying the billing procedure and improving

its accuracy

Traditionally, staff are used to spending aportion of their time manually counting platesfor billing purposes. This process is timeconsuming and error prone. This system auto-mates the repetitive and tedious billing proce-dures. It not only improves the efficiency andaccuracy of the billing procedures, but alsofrees up skills resources to maximize the valueof the human capital in a sushi restaurant.

(vi)

Providing more transparent sushi information to

diners like prices, availability, calorie content,

and so on

RFID tags can carry useful information alongwith the food, including calorie content, prices,timestamp, nutritional characteristics, andserving suggestions, all the way to an end-consumer. This food information facilitates theselection by diners of the right sushi for theirconsumption. It also introduces diners to ahigh-technology dining experience.

Some challenges in the implementation of anRFID-based sushi management system are des-cribed below.

(i)

RFID expertise for deployment

A recent survey by the Computing TechnologyIndustry Association revealed that 80 per centof the responding companies said that therewere not sufficient numbers of skilled RFIDprofessionals. Two-thirds of them said trainingtheir employees in RFID technology andeducating them about it was one of the biggestchallenges they faced in order to succeed in theRFID market (Morrison, 2005). We believethat the problem is more serious in Asia; like inHong Kong, where there is a lack of strongexpertise in RFID technology deployment.Depending on the scope of the project, theknowledge and expertise base typically covers

RFID readers and installation, RFID tags,antenna design, RFID standards, local regula-tions, RFI environmental hazards, middleware,database and web management, and so on.

(ii)

Management commitment

Gaining management commitment is one of thebiggest challenges in implementing RFID.Return on investment (ROI) is an importantconsideration for management in assessingRFID investment before RFID project com-mitment. We have to show management thatthe competitive advantage and the bottom-linetangible and intangible benefits that implement-ing RFID will bring are to its advantage.

(iii)

Cost challenges

The biggest challenge companies face withRFID is the high cost of implementation. Oneof the challenges a company faces with theintroduction of RFID technology is whetherthe business really needs the technology andhow to justify the investment in its implementa-tion. Cost–benefit analysis is critical to thesuccessful adoption of an RFID project. Atpresent, the costs of RFID adoption comprisethe major investment in hardware, applicationsoftware, middleware, and tags, and the cost ofintegrating the RFID-based system with thelegacy systems, of consultancy fees, and ofemployee training.

(iv)

Technical support for adoption

At present, both RFID hardware and softwarein Asian markets come mainly from the US.RFID solutions originate from foreign vendorswith the support of local distributors whoprovide limited technical support as most oftheir staff are marketing oriented. We havefound that most RFID hardware providers inAsian markets lack technical support staff. Thisis due to the fact that RFID is still an emergingtechnology in most Asian countries.

5. Lessons learned

Some lessons learned from this study can serveas a guideline that future implementers of RFIDsystems can adapt to their situations. We describesome of the lessons learned below.

(i)

RF site testing

Onsite testing is one of the crucial steps inassessing the readiness of a facility and possibleelectromagnetic interference (EMI) with RF

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solutions. In our study, before the developmentof the RFSM system, we conducted a survey tocheck the preparations on the premises for thedeployment of an RFID system, including pilottesting the RFID tags, the readers, and theantenna. In addition, we also carried out ananalysis of potential EMI in the restaurantenvironments like wireless networks, short-range radios, and mobile phones in order tobetter predict the site performance of our RFIDsolution.

(ii)

Top management support

Top management support is one of the keyrecurring factors affecting the success of im-plementing an RFID system. Apart fromsetting the right strategic direction, supportfrom top management can insure that sufficientresources have been allotted for the develop-ment of the RFID system. Furthermore,implementation of the new system is morelikely to bring about change like the abandon-ment of outdated processes. Resistance tochange is another important issue to confront.Continuous top management support can alsoplay a pivotal role as an agent of change tocreate an environment conducive to streamlin-ing the RFID system development.

(iii)

Competitive IT weapon

The proper use of IT is a significant enabler increating a competitive edge and enhancingcustomer satisfaction in the food industry.During the evaluation of our system prototype,food industry practitioners provided positivefeedback about the potential use of RFIDtechnology in their industry, commenting inparticular that it was beneficial for improvingfood quality control and enabling responsivereplenishment. RFID technology used inside arestaurant can also help to create a fresh diningexperience and thus enhance diners’ satisfac-tion. In the contemporary competitive foodindustry, the deployment of RFID technologycan be a weapon for market success.

6. Conclusion

Applying RFID in a conveyor-belt sushi restau-rant is an innovative idea that provides diners with ahigh-technology dining experience. It can contributeto real-time sushi quality information and increasedefficiency in food management. This case study hasdescribed the development of an RFSM system that

can be used to improve operations management in asushi restaurant, enhancing its efficiency and billingaccuracy. Though our paper focuses on the devel-opment of the RFSM system, some of the contextmay also be applicable to RFID systems in general.This study is an effort to bring ideas of embodimentinto play in the context of RFID. Through this casestudy, we have demonstrated that RFID technologycan be effectively applied in sushi restaurants tohelp improve their food safety, inventory control,service quality, operational efficiency, and datavisibility. The understanding of the developmentof RFSM projects gained from this study could beused as a foundation for conducting future studiesinvolving more RFID application projects indifferent areas and different organizations.

7. Limitations and future research

To end this paper, we discuss the limitations ofthis research and the extension of future research.First, the inherent limitation of a single case shouldbe noted. Given the single-case study, the externalgeneralizability of the findings is limited. Futureresearch can address this limitation by examiningmore RFSM systems in sushi restaurants; a largersample representing many different RFID projectswould also be beneficial. Second, in the implemen-tation of the RFSM system, every sushi dishhas to have an RFID tag embedded for trackingpurposes. RFID tags have been criticized as beinghigh cost and for unavoidably pushing up thesystem deployment costs. However, the RFID tagused in a restaurant will be in a closed loopsystem, suggesting that the cost of tags will largelybe a one-time investment (as opposed to slap andship applications in supply chain where most of thetags cannot be re-used). This expenditure will bemuch less than many other RFID applications inwhich the RFID tags often get lost during use.Third, the RFSM prototype system can only beapplied to simple sushi, which is made up of oneraw material topping only. As competition in thefood industry is keen, a retailer needs to inventsushi foods with new combinations of raw materialsin their toppings in order to retain repeat dinersand attract newcomers. Nevertheless, the lessonslearned from this case are useful to the developmentof RFID systems in the food industry. Futureresearch into the areas described below could beconducted to improve the capabilities of sushirestaurants.

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(i)

Many sushi restaurants have already providedmore sushi with different combinations oftoppings, like octopus, tuna, shrimp, tofu,egg, and cabbage leaves, to suit a variety ofdiners’ tastes. By tracking the topping selectionstatistics in the system, diners’ topping prefer-ences can be identified and prioritized; thusmore sushi with different combinations offavourite toppings can be mixed and createdto enhance diners’ appetites.

(ii)

A customer membership database can be set upfor storing diners’ personal information, visitfrequencies, visit dates and times, eating pre-ferences, and so on. Based on this information,when diners revisit the same restaurant, abetter dining experience can be achieved byoffering them personalized serving suggestionswhen they order their preferred sushi. Throughthis system, the frequent returnees can betracked and hence effective loyalty campaignscan be launched to retain and reward thosereturnees.

(iii)

One of the most important parameters ofquality control of food is the temperature. Itis feasible to consider applying RFID tocontrol and monitor the temperature of therefrigerator that stores the sushi raw materialsto further strengthen food safety control. RFIDtags with embedded temperature sensors canachieve a real-time monitoring of the quality ofthe food.

(iv)

Nowadays, people are more conscious offood safety. Traceability has become a buzz-word with regard to food, particularlyfollowing a number of food safety incidents.An end-to-end traceability of all stages in thesupply chain is desirable, right from thesource where goods and products are manu-factured, through handling, storage, transpor-tation, and delivery of a food product fromsuppliers to consumers, and all the way toinventory control and retail. Until now, RFIDapplications in the sushi industry have beenmostly proprietary and closed loop within theboundaries of a company’s operations. Ourarchitectural framework can be further ex-tended to the integrity and traceabilityof the sushi food supply chain, in order tomeet food regulations in certain countries,such as in Europe, that are concernedwith strengthening food safety control andmonitoring.

Acknowledgements

The authors are grateful for the constructivecomments of the referees on an earlier version ofthis paper. This project was supported in part byThe Hong Kong Polytechnic University under aGrant number G-YE10.

Appendix A

A.1. An illustrative example of the system prototype

Taking a look at application examples of thesystem prototype is the best way to understand theRFSM system. The illustrations in this section areintended to provide a better understanding of thesystem. We demonstrate the primary capabilities ofthe system and show how it can help to support themanagement of a sushi conveyor-belt restaurant.Annotations are added to give an insight into theoperation of an RFSM system.

Fig. A1 shows the food stock of a sushirestaurant. This screen is designed using a ‘‘red–yellow–green traffic light’’ colour scheme whichprovides available food stock information to themanager or chef for monitoring the sushi stock.Green indicates that the inventory in the shop flooris above the threshold level, yellow indicates that theinventory is below the threshold level, and redindicates that the inventory is far below the thresh-old level. The screen can be regularly and auto-matically refreshed for effective tracking of the foodinventory level, in order to achieve responsivereplenishment.

Fig. A2 shows a particular piece of sushiinformation. It provides useful food informationlike prices, calorie, and raw materials to help dinersto select their favourite sushi.

Fig. A3 shows a screen of a sushi informationdisplay board, which demonstrates the real-timesushi location on the conveyor belt. In the centre ofthe screen, there is a scrolling board, showing thecurrently available sushi provided in the shop, withits image, price, calorie content, and the number ofplates on the belt. The food information is displayedwhen the plates pass the RFID reader at the tablecorners. The plates are highlighted in red where thesushi has passed its expiry time. They are removedautomatically when passing through the corners ofthe belt.

After the meal, the waiter can use a personaldigital assistant (PDA), as shown in Fig. A4, to scan

ARTICLE IN PRESS

Fig. A1. Sushi stock monitoring.

Fig. A2. Sushi-making information.

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ARTICLE IN PRESS

Fig. A3. Real-time display of sushi position on the conveyor belt.

Fig. A4. PDA device for billing.

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the sushi plates (embedding an RFID tag in orunder the plate) with the RFID reader. On thedevice screens, information about the consumed

food, such as name and price, is shown afterscanning. A receipt can be printed for billing.

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