AN AUTOMATED PERFORMANCE MEASUREMENT SYSTEM FOR METRO OPERATIONS A. Deloukas, E. Apostolopoulou Attiko Metro A.E. 1. INTRODUCTION Performance measurement has become an important concern for public transport operators in the last decade. With regard to metro operators, the need to measure their performance has become essential, as metro systems are capital-intensive and the expectations of key stakeholders (passengers, owners, employees, community) are raised to a high level. The paper handles the development of an automated system to measure the performance of the newly started metro lines 2&3 in Athens. Attiko Metro A.E. (AM) is responsible for the development of new metro lines in Athens operating since the year 2000. The main contributions of the paper pertain to the (a) development of a measurement system of metro performance based on the balanced scorecard framework, (b) evolution of an Enterprise Resource Planning (ERP) system implemented in a metro organization to a strategic application automating performance measurement, (c) novel integration of early warning signals and what-if capabilities (anticipating future metro performance) in the Performance Management and Controlling (PMC) module embedded within the ERP system. The paper is structured as follows: Section 2 depicts the adjustment of the balanced scorecard framework so as to evaluate strategic management processes of metro operations. Four balanced perspectives constituting a chain of causal relationships are contextualized. The objectives developed within the four perspectives are translated into a set of measures, termed Key Performance Indicators (KPIs). A detailed account of the KPI system is given. Measured performance is compared against benchmarks and, in case of low effectiveness, actions are proposed to improve metro performance and achieve the target benchmarks. In section 3, ERP systems, their risks and benefits are described in generic terms. A case study of an ongoing ERP implementation in the Athens metro organization is presented. Section 4 addresses the automated performance measurement system which facilitates the actual implementation of initiatives established within Attiko Metro s 20-year Business Plan. The respective PMC module enables the monitoring of metro performance in real time. The system tracks the KPI values against the target benchmarks. The use of key drivers of future performance advances PMC module reporting to an early warning system. The integration of a unit-cost allocation model of metro operations to the same
module allows the running of costing scenarios, thus facilitating strategic decision-making. 2. LINKING MANAGEMENT PROCESSES 2.1. A Framework for Performance Measurement Several conceptual frameworks have been proposed in the recent past years to evaluate the overall performance of organizations beyond pure economic considerations. Comprehensive approaches as the Baldridge model or the European Foundation for Quality Management (EFQM) standard focus on quality aspects, other like the Balanced Scorecard (BSC) concept maintain an equilibrium between financial objectives and key drivers of organizational performance (OLVE, ROY and WETTER 1999). Common to these evaluation frameworks is the linking of a wide range of management processes. Relevant processes refer to: (1) identifying business strategies, (2) translating strategic objectives into measures, (3) setting performance targets for the measures and developing action plans to achieve them, (4) enhancing feedback on controlling performance and corrective actions. Attiko Metro is the organization that has been established to manage the construction and to operate the new metro lines 2&3 in Athens. AM set up in stages during the year 2000 a metro system of 17kms in length. Extensions to the metro giving an additional 11kms are currently under construction, and scheduled to be in operation before the 2004 Olympic Games. An objective of this paper is to describe the system developed for strategic monitoring of metro performance. What is striven for is a balanced metro performance across multiple perspectives. The principles of the BSC framework have been substantiated to adjust to the particular organizational context. Starting from strategic initiatives assembled within the 20-year Attiko Metro Business Plan (B*A&H and PLANNING 1998), relevant business strategies are transformed into multiple objectives of critical importance, belonging to four perspectives shown in Diagram 1. The methodological framework provides a balance between financial outcomes of the operations (e.g. cost recovery ratio) and the drivers affecting the future performance of those outcomes. A cause-and-effect relationship between the four perspectives is set out in this Diagram. Employee satisfaction has been assessed as a very basic resource of efficient business processes (e.g. productivity growth). The latter processes determine quality of service satisfying the passengers (e.g. service reliability). The level of service along with the efficiency of business processes have, after all, a strong impact on the future financial effects of metro operation.
EMPLOYEE SATISFACTION BUSINESS PROCESS EFFICIENCY CUSTOMER SATISFACTION / SERVICE QUALITY FINANCIAL OUTCOMES Diagram 1: Cause-and-Effect Relationship of Metro Operator s Perspectives The rationale behind the choice of the four perspectives is that to focus on financial aspects only is inadequate for business decision-making. For instance, cost-cutting initiatives do not make sense if they seriously compromise the service standard set. On the other side of course, an underpricing of services may increase the customer satisfaction in the short term, while worsening the financial outcomes. The key drivers of performance depend on the organization type and the business scope (ATKINSON, WATERHOUSE and WELLS 1997). The key value driver of metro operations is the customer capital (passenger satisfaction), whereby a maximization of the cost recovery ratio is aimed. The critical driver of the metro construction management will be the human capital of the company, whereupon the focus is on project cost reduction. To explain non-financial perspectives further: human capital being an intangible asset, the employee satisfaction may be considered as a proxy of the organizational climate, which is important for the long-term development of the company. The efficiency of core processes refers mainly to labour productivity and capital (e.g. vehicle) utilization. The duty roster efficiency (train-kms/driver) becomes of critical importance for metro operations. Effective core processes create value for the customers. Customer-driven aspects of metro operations are the service quality and the safety, both being preconditions of customer satisfaction. 2.2. Selection of Key Performance Indicators The measurement system of the metro performance has been deductively evolved to match the proposed methodology. Broadly speaking, it combines aspects of cost, time and quality. The objectives developed within the four perspectives are translated into a set of measures, termed Key Performance Indicators. The KPIs relate input resources and factor costs (labour, energy, materials), service production (e.g. veh-kms, quality level), as well as service consumption variables (e.g. ridership, revenue), as shown in Diagram 2.
Input resources / factor costs Labour (staffing) Capital (e.g. # RS vehicles, materials) Energy (traction power) COST - EFFECTIVENESS Productivity measures COST - EFFICIENCY Service production Vehicle - kms Seat - kms Service availability Service reliability (regularity) SERVICE - EFFECTIVENESS Provided output Service consumption Diagram 2: Conceptual interrelationship of marker variables Passengers Passenger - kms Farebox revenue Safety (accidents) The decision sciences formulate desirable properties for the metrics to be selected, such as relevance, controllability throughout the organization, reliability and, of course, measurability. The selected KPIs measure more or less directly (as proxies) various aspects of the objectives to be evaluated. The selection of KPIs required structured discussions with senior managers of the company. The resulting KPI system (reviewed in a top management workshop) consists of 21 high-level KPIs. The KPIs have been defined as ratios to preserve scale independence. Multifaceted objectives, such as employee satisfaction, train availability and reliability, labour and vehicle efficiency are measured by more than a single KPI. However, it is not assumed the contributory KPIs to have the same importance for the particular goal achievement. The present KPI system is confined to objective measures based on metro usage data. Nevertheless, intersubjective measures resulting from repeatable surveys (e.g. customer satisfaction surveys) could be also incorporated. Financial objectives and corresponding KPIs pertain to cost efficiency (operating costs/veh-km), cost effectiveness (operating costs/passenger), degree of outsourcing (outsourced expenses/operating costs), revenue ratios (farebox revenue/ridership, ancillary revenues/operating revenue), and cost recovery ratio (operating revenue/operating costs). The customer-oriented objectives and related KPIs refer to train service availability (mileage operated as % of scheduled mileage, %-age of peak train cancellations), train service reliability (actual train runs with delay <2min as % of scheduled runs, failures causing delays/10.000 veh-kms), in-vehicle peak
crowding level (standees/sq.m.), station service quality (escalators service time operated as % of planned service time), and safety (passenger injuries/10.000 veh-kms). The business efficiency objectives and KPIs pertain to labour efficiency (employees/10.000 veh-kms, employees/route-km, train-kms/driver, RS maintenance employees/vehicle), and vehicle efficiency (veh-kms/vehicle, peak vehicles/active vehicles). Finally, the employee satisfaction KPIs refer to the employee turnover rate and the non-attendance rate. 2.3. Setting of Benchmarks and Action Plans The AM Business Plan set out a normalized comparison with best practices of competitive European metro systems. The benchmarking technique has been used in order to set the desired target for each of the KPIs. Barcelona and Vienna have been selected as comparable metros to be benchmarked. Similar KPIs are the base for comparison. Apart from the high performing KPIs of both metros, the root causes of their business practices have been studied in detail to ensure that best practices are really represented (e.g. high degree of outsourcing distorts labour productivity indicators). The benchmarks were to stand for high but realistic (to-be) targets for the metro organization. A measurement system without given target values would be a weak concept. The derived target benchmarks represent a demand, such as a significant reduction in input factors utilized or a substantial increase in quality achieved. Action plans for the non-financial objectives are to be developed in order to attain the targets. The financial objectives are not considered but supposed to reflect plan outcomes of the non-financial objectives. An actual push on the performance drivers is assumed to enable sustainable financial results at a later stage. Compensation incentives counteract unplanned employee turn over, absenteeism and labour inefficiency. Standardization of operating procedures and adoption of new technologies may support higher process efficiency. Quality control initiatives lead to less accidents or failures causing train delays. 3. ENTERPRISE RESOURCE PLANNING SYSTEM OF ATTIKO METRO 3.1. What is an ERP system? Prior to 1990 s, organizations used paper-based or stand-alone software applications to manage clusters of business processes such as maintenance, warehouse or finance. These applications were mostly not integrated. The growing needs for a better co-ordination as well as the advancement of distributed processing within integrated client/server architectures, resulted into business system solutions, called Enterprise Resource Planning Systems. An ERP-related project is accordingly more than a simple IT project, it is a business project linking most of the divisions and processes of an organization.
An ERP system allows an organization to: - automate and integrate most of its business processes - share common data across the entire organization (unique identifier for each item) - maintain data integrity and consistency - produce and access information in real time. ERPs are typically semi-finished products with pre-determined tables and settings, in-built process chains based on good practices, functional procedures adapted to the local legal framework (e.g. tax law, social security requirements, accounting system), and many parameters to be configured by the adopting organization. The implementation of an ERP system is much more about modifying of existing business processes to adapt better practices embedded within the ERP, than about adapting the ERP-code to existing business processes (JOCHEM 1998). The former case necessitates change management processes to improve acceptance level within organization. The latter case makes sense only when effective unique processes need to be preserved. Ideally, ERP parameterization and (re-)engineering of business processes are to be done in parallel (TENG, GROVER and FIEDLER 1994). 3.2. Risks and Benefits of ERP systems The use of ERP systems by transport organizations became widespread in the last decade due to their value generating features. Operational benefits refer mainly to the automation of routine tasks and removal of redundant timeconsuming transactions (information flow across business functions). Managerial benefits relate to better resource management (e.g. maintenance control, workforce allocation, stock replacement), informed decision-making and improved performance (e.g. business control and monitoring due to centralized information and data analysis capabilities). Organizational benefits refer largely to integrated business processes (e.g. less redundancies and conflicts), better business system co-ordination and increased accountability for decision-takers. For instance, Finance could know every time the status of a purchase order without having to ask the Warehouse or the Procurement. Prior separate suppliers files of Finance, Warehouse or Procurement are consolidated to one table without duplications and following a unique coding scheme. However, it is difficult to quantify the resulting cost savings of reengineered processes and changed workflows due to the ERP usage. The use of multiple ERP modules produces economies of scope and synergies, due to the higher degree of functional integration provided. Intangible benefits seem to dominate the overall ERP value generation (HITT, WU and ZHOU 2002). On the other hand, ERPs entail high-cost and high-risk projects. The immediate costs refer to substantial implementation costs, as well as license, training, maintenance and hardware costs. The associated implementation risks consist of critical business risks (e.g. resistance to change, loss of ERP
key users, schedule overruns) and less critical, technical uncertainty (e.g. no further s/w development by the vendor). The use of multiple ERP modules may generate diseconomies of scope (e.g. higher complexity, wider propagation of user errors). An important issue is the longer time-frame required for an ERP system evaluation. Whereas initial ERP expenditures are high, benefits begin to accrue 2-3 years after the full system goes live, in order for organizational learning to have occurred. During the ERP implementation itself there may even be performance reduction. The expected useful life span of an installed ERP system ranges from 8 to 15 years, depending mainly on s/w technology advancements and the change of the business needs. 3.3. The ERP system of Attiko Metro The 20-year Business Plan for Attiko Metro proposed the implementation of an ERP system for metro operations as a strategic initiative. A proprietary ERP system (BAAN) is currently implemented in AM, to cover important business processes of metro operations as well as metro construction management. The ERP standard software (BAAN IV) is based on the ORACLE 8 database platform and is licensed for about 200 concurrent end-users (WENZEL and POST 1998). The network consists of interconnected LANs at Attiko Metro head offices, Sepolia Depot, Operations Control Center, all connected together (see Diagram 3). During 2001 AM created an operating company (located at Sepolia Depot) to run L2&3. About 60% of the ERP end-users are currently placed at the Sepolia Depot. AM remains owner of the metro system and the operating company operates, maintains and manages the system. Therefore a financial link between both companies exists. Diagram 4: ERP Module Interrelationships A M H e a d O f f i c e s Finance Procurement Human Resources Performance Management Finance Duty Mgt AMEL Sepolia Depot Material Management Maintenance Mgt Procurement Timetable Scheduling Human Resources Finance Fare Collection Operations Control Center Timetable Mgt Duty Management Service Monitoring Incident Reports Duty Mgt Stations Fare Collection Incident Reports Material Mgt Duty Management Diagram 3: Functional Topology of the ERP System of ATTIKO METRO
The modular architecture of the ERP system integrates activities of Maintenance, Warehouse, Procurement, Finance and Human Resources based on a single database. The metro operation depends on maintenance of the track, rolling stock and fixed equipment. The scheduling and control of both preventative and corrective maintenance workflows is organized through ERP work orders. The Maintenance module uses repair materials (spares) provided by the Warehouse module. The latter module, sometimes called Logistics, takes over distribution of stock items and replenishment orders. Operations (automatic train supervision, fare collection, scheduling and rostering) are, however, covered by stand-alone applications. The Procurement module is used throughout the whole company for purchasing of goods and services. It depends heavily, as most of the modules, on order processes. Finance contains General Ledger, Analytical Ledger by cost center (sources of expenses), accounts payables/receivables, budget control, revenues and fixed asset depreciation submodules. The Human Resources module is less integrated than the other modules, it combines payroll and personnel management functions. The implementation of each module occurred in three distinct phases. In the first mapping phase, the existing business processes have been analyzed and the business requirements defined. In the next piloting phase, the to-be process chains and data structures have been designed in detail, and the ERP parameterization has been planned. The third migration phase contains parameterization, data transfer, testing, training and documentation activities. Finally, the cross-functionality and integration of all modules has to be checked. A sequential strategy for the implementation of the entire set of modules has been adopted (SCHWARTZ 2000). In a first stage, business processes have been engineered in parallel with the ERP customization for the core activities of Maintenance (a rarity for European metros) and Warehouse. Both core activities has been given high priority by the Business Plan, in view of the forthcoming opening of the metro operation. In a subsequent phase, the ERP modules for administrative functions have been parameterized. The existing operating procedures have been reengineered to fit with the ERP in-built processes. The interrelationships of the five base modules are shown in Diagram 4. Since the metro divisions can share information and communicate with each other, the introduction of ERP technology is expected to lead to improvements in the future metro performance. For instance, warehouse shortages are revealed in real time, so inventories may be reduced. Duplication of data entries for order processes is eradicated. Financial reporting becomes more transparent and detailed, so that accountability increases.
HUMAN RESOURCES PROCUREMENT FINANCE MAINTENANCE WAREHOUSE Diagram 4:ERP Module Inter-relationships 4. ERP-BASED PERFORMANCE MANAGEMENT AND CONTROL 4.1. Attiko Metro s Performance Management and Controlling Module The need for business intelligence to make strategic decisions has not been a focus of ERP implementations in the past. ERP systems were mainly transactional applications, not providing strong analysis and reporting capabilities suited to manage the overall organization. ERPs are still not optimized to perform complex data transformations that involve information from across business functions. Many organizations have recourse to dedicated data warehouse tools based on predefined queries and content reports. It is preferred, however, to develop the ERP system as a strategic application taking advantage of the transactional information lying within the data warehouse of the system itself. For that purpose a Performance Management and Controlling module has been developed as an application embedded within the ERP system of AM. The PMC module enables the automated monitoring of the overall performance of metro operations. It supports strategic management rather than operational processes (MARTINSONS, DAVISON and TSE 1999). Automated features of the PMC module are: (a) periodic calculation of KPIs, (b) comparison with external target benchmarks, (c) monitoring of internal performance variability over time, (d) prediction of performance through whatif scenarios calculation. The PMC module extracts and transforms consistent information from different sources. The sourcing scheme for calculating KPIs is shown in Diagram 5.
BAAN - FINANCE General Ledger accounts and / or dimensions HUMAN RESOURCES Mgt System Staff - related data BAAN - FINANCE REAllocation accounts SOURCE 1 SOURCE 2 SOURCE 3 External Operational Data ( ATS, IVU, AFC etc. ) BAAN - PMC Key Performance Indicators Diagram 5: Sourcing Scheme for Calculating KPIs in the PMC Module Financial data of General Ledger accounts and dimensions are consolidated through the costing (named Reallocation ) submodule, staff-related data are drawn from the Human Resources module, and external operational data are entered through cold links from other applications (automatic train supervision system, train scheduling software system). Each of the five ERP base modules provides an integral but single-dimensional access to the database, while PMC provides a multi-dimensional access. Note that the detailed financial accounts and staff categories are regrouped in a manner that transcends the simple book-keeping function in order to support a strategic decision-making. The aggregations are fully compatible with the related categories used in the AM Business Plan. Using the Enterprise Performance Manager functionality of BAAN: (a) the calculation rules for KPIs are defined, (b) actual and target KPI values are linked, (c) the interrelationships between the KPI components have been fixed (see Diagram 6). KPI ALGORITHMS DEFINITION AND PARAMETERIZATION OF THE KPIs P M C LINKING OF KPIs AND FISHBONE DIAGRAMS KPI RELATIONSHIPS DEFINITION OF THE ENTERPRISE MODELS AND DEVELOPMENT OF THE FISHBONE DIAGRAMS KPI VALUES VS. BENCHMARKS RELATIONSHIP Diagram 6: Linking of Business Process Metrics
Cause-and-effect chains ( if-then statements) in the form of fishbone charts describe, within the PMC module, the multiple components ( causes ) of an activity measure ( potential problem or effect ). In fact, the achievement of hierarchically lower goals influence the achievement of higher-level goals. Only measures that are elements in a chain of cause-an-effect relationships are considered. An example pertaining to the cost recovery ratio and its components is demonstrated in Diagram 7. It enables a visual alert by underperformance ( what is happening ), so that an exception analysis ( why is happening ) and corrective actions are possible without delay. Especially, the use of non-financial indicators of future performance constitutes a novel early warning system, anticipating forthcoming problems.???5 : OPERATING COSTS KPI 1: SALARIES KPI 2: POWER COSTS KPI 3: MATERIAL COSTS KPI 4: MISCELLANNEOUS KPI 7: OPERATING COST RECOVERY RATIO KPI 6: OPERATING INCOME Diagram 7: Linking of KPIs with the Fishbone Diagrams (ISHIKAWA) 4.2. PMC Reporting and Exception Analysis The full set of measures refers to monthly reported KPIs and a subset of weekly KPIs. The generated KPI reports contain actual and cumulative (last 12-months average) values. An accompanying exception report is a strategic controlling tool providing insights about problem areas. It monitors the performance variance over the reference period and identifies the root causes in cases of underperformance. A typical excerpt of the KPI report containing customer-driven service quality indicators is displayed (Table 1). KPIs may be calculated at various level of detail (overall, business unit or metro line). In the presented table all moving average indicators of train service availability and train service reliability exceed targeted performance.
Month: May 2001 Target Actual Moving Average Related ID A. Quality KPIs Benchmark Monthly Performance Marker Notes Performance (01/06/00-31/05/01) Variables A1 Train service availability Kilometrage operated as % of scheduled >96% 91,2% 96,9% 1,2 Strike on 17/05/01 kilometrage (BP) A2* %- age of peak period train cancelations <2% L2: 0,3% L2: 0,1% 5,6 per line L3: 0,8% L3: 0,4% A3** In-vehicle peak crowding level <5 standees / sq. m. standing area L2: 2,5 L3: 1,1 4 L2 survey on 24/04/01(OMO PAN) L3 survey on 24/04/01(SYN EVA) A4* Train service reliability # of actual train runs per line with delay < 2 min from scheduled headway as % of scheduled runs L2: 99,9% L3: 99,9% L2: 99,8 % L3: 99,5% 7,8 Regularity indicator A5 # of failures per 10000 veh-kms operated <0,33 (BARCELONA) 0,26 0,28 1,9 Failures inducing cancellations or delays >2 min from scheduled headway A6 # of peak period train stops with dwel time 10 > 60 sec A7 Station service quality Escalators/ lifts service time operated as % of planned service time >98% Escal: 99,9% Lifts: 99,9% Escal: 99,9% Lifts: 99,9% 11 Planned annual service and time to alert OCC reduce further the planned service time A8 Peak period passengers waiting > 2min at < 1% 2,2% 12 Survey conducted in Omonia ticket outlets as % of tickets sold on 31/03/00 * : KPIs A2 and A4 have been calculated considering OCC ad-hoc modifications of timetable. ** : KPI A3 has been calculated considering the unevenness factor 0,85. Therefore, the effective standing area is 134 sq. m./train (=0,85*158 sq. m.) Note: Since October 2000, KPI A4 is based on regularity (time period between consecutive runs) instead of punctuality (time deviation from scheduled runs). The new measurement of reliability takes into account al delays more than 2 minutes from scheduled headway. Table 1: Monthly KPI Report 4.3. PMC and What-If Scenarios A value-adding functionality of the PMC module is, that it does not only monitors past performance, but also gives guidance about future performance through what-if scenarios calculation. Business scenarios may refer to altered train schedules, work rules or passenger demand, i.e. changing outputs such as veh-kms, train-hours, peak hour vehicles or ridership. The base algorithm is a unit-cost allocation model of metro operations, calibrated for a base year 1. Cost predictions are a function of input prices (labour, energy or material unit-costs) and fluctuating outputs. Costing scenarios are run by the Reallocation submodule. The PMC module capability thus goes beyond performance measurement and business reporting. Through what-if
scenarios it assists business planning and decision-making at the managerial level. 5. CONCLUSIONS The paper has considered the adjustment of the balanced scorecard framework to measure and evaluate strategic processes of metro operations. Four evaluation perspectives have been proposed for the new metro in Athens. Specific metrics have been considered for the more detailed strategic objectives. The resulting KPI system assesses performance against target benchmarks periodically. This controlling function in essential to identify business processes demanding quality improvements. In this respect, the high-level measures of metro performance place quality management within a strategic context. The automated strategic measurement system presents an innovative management tool to monitor and guide metro operations. Automation allows metro management to obtain strategic performance-related feedback without delay. The aim is to assist managerial decision-making based on solid information rather than intuition. Stored series of time-stamped KPI values enable a statistical estimation of the impacts of action plans on performance. PMC, as a decision support system (answering what-if questions) is equivalent to setting a hierarchy of multiple non-redundant objectives, leading to a set of measures quantifying future cost performance. The PMC module developed links performance measurement, benchmarking and business planning. It is therefore a comprehensive tool for strategy implementation. The automated performance monitoring of strategic processes in the case of the new Athens Metro may be prospectively considered, within an international context, as a good practice. However, further experience is needed in order to determine whether the proposed measures build up a sufficient set. Areas that need future investigation concern data reliability, benefits and satisfaction with PMC usage after implementation, adequacy to the managerial processes involved, and its long-term impact on metro performance. Notes 1 The unit-cost model has the following form: Total Operating Costs = = a*train-hours (TH) + b*veh-kms (VKM) + c*ridership (RIDER) + + d*peak Hour Vehicles (PHV) where: a*th = Passenger Service Costs (labour costs of train & station personnel) b*vkm = Maintenance of Equipment (rolling stock, fare collection etc.) + Maintenance of Ways&Sructures (track, stations, tunnel,
depot, systems) + Power Costs Maintenance costs contain labour and materials c*rider = Other costs (transit authority compensation, ticket sellers & inspectors) d*phv = Administration costs (general or indirect costs of administrative divisions and other overheads) dedicated to Operations as well as cleaning, security and other attributable costs The unit-cost rates {a, b, c, d} are inputs to be updated every year. REFERENCES Atkinson A., J. Waterhouse, R. Wells (1997), A Stakeholder Approach to Strategic Performance Measurement, Sloan Management Review, Vol. 38, pp.25-37. B*A&H and Planning (1998) Attiko Metro 20-year Business Plan, Stages II and III, Final Report, Athens. Hitt L.M., D.J. Wu, X. Zhou (2002), Investment in Enterprise Resource Planning: Business Impact and Productivity Measures, Journal of Management Information Systems, Vol. 19, pp. 71-98. Jochem, M. (1998) Einführung Integrierter Standardsoftware: ein Ganzheitlicher Ansatz, Lang, Frankfurt. Martinsons M., R. Davison, D. Tse (1999), The Balanced Scorecard: A Foundation for the Strategic Management of Information Systems, Decision Support Systems, Vol. 25, pp.71-88. Olve, N. G., Roy, J. and Wetter, M. (1999) Performance Drivers: A Practical Guide to Using the Balanced Scorecard, Wiley, Sussex. Schwartz, M. (2000) ERP-Standardsoftware und Organisatorischer Wandel, Gabler, Wiesbaden. Teng J., V. Grover, K. Fiedler (1994), Redesigning Business Processes with Information Technology, Long Range Planning, Vol. 27, pp.95-106. Wenzel, P., Post H. (1998) (Hrsg.), Business Computing mit BAAN, Braunschweig, Vieweg.
Disclaimer The views expressed in this paper do not represent official views of Attiko Metro A.E., the authors being solely responsible for the views expressed herein.