Reference Framework Proposal for the Management of a Warranty Program Vicente GONZÁLEZ DÍAZ, Carlos PARRA MÁRQUEZ, Juan GÓMEZ FDEZ., Adolfo CRESPO MÁRQUEZ Department of Industrial Management, School of Engineering, University of Seville Camino de los Descubrimientos s/n. 41092 Seville, SPAIN Phone: +34 954 487215, FAX: +34 954 486112 E-mails:
[email protected],
[email protected]
Abstract
The objective here is to propose a reference framework for the management of warranty assistances, using certain engineering techniques for similar processes, and according to a process-based quality management system. Therefore, regarding the warranty management process, a generic framework is presented integrating management models already developed and found in the literature. They will be gathered in four sequential steps or managerial blocks, where the different techniques will play a crucial role. Following this scheme, a framework is defined as a support for the management of a warranty program, offering together a practical vision of the set of activities which compose each managerial block, and focused on the improvement of the relationship between manufacturer and user. By reengineering of managerial processes and by the application of a correct warranty management is possible (among others features) to influence in the product design and/or manufacturing, increasing its quality by the enhancement of the information flow about product defects and their sources. The result of the study is in few words a classification of different engineering tools, focused mainly on the improvement of the warranty program and product management, enhancing in parallel maintenance and manufacturing aspects, and discussing briefly the proper use of each tool or technique according to the data or information available. Acknowledgements The author would like to thank the reviewers of the paper for their contribution to the quality of this work.
1.
INTRODUCTION
In every field, any management process can be usually split in two basic parts: a moment for “thinking” and a moment for “doing”. That means there is a time to define a strategy, and another time to implement such strategy [A. Crespo Márquez et Al. (2009)]. Related to the management of a warranty program, the first part will require the definition of warranty targets, which will be derived directly from the business plan. These objectives will be not only to decrease costs, but also (and very important) to purchase a reliable product, offering an appropriate after-sales service to the user. In general, the definition of the warranty program strategy will determine the success of such warranty service, conditioning of course the implementation of plans, schedules, controls and improvements. The second part of the warranty management process (the implementation of the selected strategy), will face different difficulties. These difficulties can be for instance the capability to assure proper skill levels in the staff, to carry out correctly the work planning and the schedule fulfilment, or to assure the use of suitable tools, among others. Basically in this study, a generic framework is proposed for the management of warranty assistances with the intention of improving the quality of the product avoiding weak points during the manufacturing and, consequently, reducing costs from the after-sales service. In order to reach these purposes, the experience and the data gathered during the warranty assistances must be used as a
Time rate
feedback to the engineering/manufacturing process.
Act, Decide, Solve ("Doing ") Plan, Schedule, Organize ("Think ing ") Control, Verify, Review ("Doing ") Study, Analize, Calculate ("Think ing ")
Actual dedication
Desired dedication
Figure 1. “Doing” and “Thinking” in warranty program management (Adapted from A. Crespo Marquez, 2007)
Along four steps, this framework will include, as mentioned, moments for “thinking” and moments for “doing”, just in order to perform finally an adequate service to the customer in a satisfactory way, applying a continuous improvement of the warranty management process and, consequently, a continuous improvement of the whole productive system.
2.
THE WARRANTY MANAGEMENT PROCESS
Management is usually defined as a process for leading and directing all or part of an organization. In our case, the warranty management process will suppose consequently the course of actions, series of stages or steps to follow, in order to lead and direct the organization of a warranty program. As it is shown in figure 2, a warranty program management, viewed from a strategic perspective, begins with a strategy linked to technical and commercial planning from the very start of the product development process [D. N. P. Murthy, W. R. Blischke (2006)]. The steps in this scheme happen in many cases simultaneously, hence an aftersales support (for example) is frequently offered while the production line is still open. That means, that the information obtained from this aftersales service can be very helpful for the production lines and, of course, very useful to improve the design and development of the product [V. González Díaz et Al. (2009)]. For such context is exposed here a proposal for reference framework. PRE-LAUNCH POST-LAUNCH
Front-End Design & Development
LAUNCH
Marketing Aftersales Support
Production
Feedback
Figure 2.Product life cycle – warranty perspective (Adapted from D. N. P. Murthy, W. R. Blischke, 2006)
In addition to this brief definition about the management of a warranty program and its inference on the product life cycle, there are currently different international standards which pretend to approach the whole business activity, dividing this in a chain of processes. The management process defined in such standards usually fulfils the following features [L. Mihok (2004)]:
Customer focus.
Leadership.
Involvement of people.
Process approach.
System approach to management.
Continual improvement.
Factual approach to decision making.
Mutually beneficial supplier relationship.
Particularly, the EN-ISO 9000/2000 defines a Quality Management System, which is designed to attend the needs of all interested parties. That is, customers, suppliers, employees and owners.
In any case, using the model of a process-based quality management system in a simply way and adapted to the warranty management, it is possible to obtain an approach shown in figure 3. This adjustment to the warranty management process is thanks to the flexibility of the standards, since they are applicable to all kind of work organizations, regardless the type of their business and their size.
C U S T O M E R
E X P E C T A T I V E S
EFFICTIVENESS -Step 1-
EFFICIENCY -Step 2-
WARRANTY MANAGEMENT PROCESS
ASSESSMENT -Step 3-
INPUTS Information Flow
IMPROVEMENT -Step 4-
OUTPUTS
S A T I S F A C T I O N
C U S T O M E R
Value-Adding Activities
Figure 3. Approach for a Warranty Management Process matching the ISO model
On the other hand, the reason to select these four steps in the warranty management process (effectiveness, efficiency, assessment and improvement), which will be used as a base for the proposed framework, is justified as follows.
The first step is related to the Warranty Program Effectiveness. Here it is defined the warranty objectives, priorities and strategies, as well as those key indicators for the proper performance of the warranty program. In this moment, it is important the soon intervention on those already detected weak points with high impact on the customer satisfaction. Effectiveness shows how well the company (or particularly, the after-sales department) meets its goals or fulfils the customer/company needs. It is often discussed in terms of the quality of the service provided, viewed from the customer’s perspective. This will allow us to arrive at a position where we will be able to reduce warranty costs associated ultimately with customer dissatisfaction. In the case of warranty, effectiveness represents the customer satisfaction related to the capacity and condition of the company assets or, in other words, the reduction of the after sales company cost because product service is available for the user when it is needed. Therefore, effectiveness concentrates itself on the correctness of the warranty process and if such process produces the required result.
As a second step it is considered the Warranty Program Efficiency. That is to attend warranties with minimum waste, expense, or unnecessary effort. Efficiency is therefore understood as the provision of the same or better service under the same cost, giving a measure on how well the warranty assistances are being performed. The warranty support efficiency can be considered as the ratio between the planned or expected resources necessary to fulfil the required warranty task and the resources actually used. By the properly performance of this step, it is possible to obtain not only a fast and relevant enhancement in terms of reliability, but it is also possible to assure a very effective definition of the warranty plan activities from the aftersales department.
The third managerial block is devoted to the Warranty Program Assessment. In order to assess the warranty service, is needed to use suitable measures which should be defined during the strategy phase of the warranty program. The measures in general must enable mainly the comparison of reliability data as well as the inclusion of the life cycle cost assessment. Once warranty assistances are done, or based on a periodical review to the product performance, is when the warranty program assessment must be carried out. The company should therefore establish and use a standard and repeatable method for collecting and analyzing data and interpreting results, which may be based on corporate or industry factors. The results should be used to support and justify enhancements.
Finally, the fourth step is related to the Warranty Program Improvement. This will be made based on accepted management performance indicators. As everyone can imagine, with the already mentioned steps, there is a huge amount of data related to warranty with a wide variety of information.
Technology infrastructure
E-Procurement E-Business
Asset management Real-time data
Condition-based monitoring
Collaborative planning E-Manufacturing
E-Warranty
Predictive technologies
Trading exchanges
Real-time information
Outsourcing
Dynamic decision making
Figure 4. Integration among e-warranty, e-manufacturing and e-business system (Adapted from Koç M, Ni J, Lee J, Bandyopadhyay P. 2003)
To assure the continuous improvement cycle is therefore necessary a computerized information system for the warranty program, which can enable the cyclical process of managing data and analyzing results. In this step is included the concept of E-Warranty (see figure 4), which can increase the possibilities to use information from multiple origin and from different types, to process larger volumes of data and make more advanced reasoning and decision-making, as well as to implement cooperative activities.
3.
MANAGEMENT
FRAMEWORK
FOR
A
WARRANTY
PROGRAM In this section, we will briefly introduce blocks and methods that may be used to improve the decision-making process. The reference framework proposed for the management of a warranty program supposes here the essential supporting structure and the basic system needed to manage such program, and influencing on the engineering/manufacturing phase.
3.1 First Step: Warranty Program Effectiveness In order to avoid strategical contradictions between the warranty program and the overall business management, it is proposed the application of a Balanced Scorecard (BSC) model. Basically, this
INTERNAL PROCESSES Means to achieve the financial and custom er objectives.
VISION AND STRATEGY
LEARNING AND GROWTH The capability to im prove and create
CUSTOMER The perform ance attributes valued by custom ers.
Figure 5. Perspectives to reach goals by a Balanced Scorecard
BSC applied to the management of a warranty program can involve the following steps:
INICIATIVES
TARGETS
OBJECTIVES
FINANCIAL The investor's point of view .
MEASURES
model considers targets and goals around four perspectives as it is shown in figure 5.
a) Strategical formulation for the warranty program (such as the outsourcing [J.F. Gómez et Al. (2009)] of warranty assistances, or the development of warranty teams with multiskilled technicians). b) Translation of warranty strategic into middle-term reachable objectives (such as the identification of measures designed to pull people towards an overall vision). c) Development of action plans (in order to reach the targets identified in step b, and taking into account any necessary changes in the organization's support infrastructure). d) Periodical review of performance and strategy (just to quantify the progress in order to formulate new strategic objectives, action plans or the revision of the whole scorecard).
Once the warranty program objectives and strategy are defined, is necessary to determine the product criticality. The Criticality Analysis is understood here as how crucial is the complaint of a client due to a failure and its consequences to the business. Decisions and actions from the warranty program can involve the possibility of a certain deviation from business objectives (in terms of profit losses, redirection of resources, possible delays, use of assembly pieces as spares, etc.). Therefore,
it
is
required
the
application of a technique which help
S tep 1: EFFECTIVENES S
systematically to decide which assets Balance Score Card
should have priority related to the management
of
the
Criticality Analysis
Failure Root Cause Analysis
warranty
program, in accordance of course with the existing program strategy.
Figure 6. First Step, proposed for the Warranty Program Effectiveness
One of these techniques can be based for example on risk-cost assessment. The Criticality Analysis based on risk-cost combines the probability of an occurring event, with the impact that this event would cause. As a result, we obtain a criticality matrix which offers a prioritized view of probable events related to warranty issues, which allow us to align aftersales actions with the business targets. By this way, it is possible to foresee where to apply available resources to mitigate risk reducing warranty cost and customer dissatisfaction.
Finally, when the strategy to follow has been defined and the probable events have been prioritized, it is the moment to focus on those customers’ complaints related to repetitive or chronical failures that supposes high priority events. If it is possible to find and to eliminate the causes of those failures by a
soon intervention, it will provide a fast and important initial advantage of the warranty program strategy. Anyway, there are different methods already developed to perform this analysis of weak points. For instance, the Failure Root Cause Analysis considers actions in order to discover the reason of the appearance of a specific failure, and how to correct its causes. A first classification of the causes could be of course if the failure must be attended under warranty or not (see figure 7). This analysis will help to readapt the considerations taken initially on the Balance Scorecard, improving by this way the warranty program effectiveness.
Causes Still Unknown - This area reduces itself
Complaints under warranty
by the experience. - Related costs are in principle unexpected.
Complaints of customers
Causes Already Known - First approach based on m aintenance data. - Related costs are under control.
Possible Failures under warranty
Figure 7. First classification of causes (emphasis on those warranty complaints whose causes are still unknown)
A detailed root cause failure analysis may consist of:
Determine a root cause of failure;
Forming a team of experts;
Proposing, testing and validating hypotheses;
Gathering evidence;
Recommending preventive actions;
Analyzing the results and determining
Implementing improvements;
failure causes.
3.2 Second Step: Warranty Program Efficiency To attend warranties with minimum waste, expense, or unnecessary effort is necessary to design an adequate plan for the warranty program. The plan for a certain product will require identifying its functions, the way these functions may fail and then, to establish a set of applicable and effective tasks, based on considerations of product safety and service economy. A method which can help to elaborate such plan at the very beginning of the warranty program can be extracted from management techniques of the maintenance field. Particularly, it will be useful the application of an adapted
Reliability Analysis and Maintenance Design Tool (RA & MDT), as for instance using FMECA
RA & MDT
for generic maintenance plan design.
INFORMATION SHEET
DIAGRAM AND DECISION SHEET
1. What are its functions? 2. How can it fail? 3. What does the failure cause? 4. What happen w hen it fails? 5. What are the consecuences of the failure? 6. What can w e do to prevent the failure? 7. What can w e do if it is not possible to prevent the failure?
Application to WARRANTY Failure know ledge com es from the com plaint of a custom er.
Figure 8. Implementation of the RA & MDT method to the Warranty Casuistry
An initial maintenance plan, applied to the warranty time horizon, can suppose a good first approach for the warranty capacity planning, the spare parts provisioning, the warranty task schedule, skill level of the technicians etc.
Figure 9. Integrated model for total warranty costs (Adapted from K. Lyons and D.N.P. Murthy 2001)
The planning and scheduling improvement applied to a warranty program can of course enhance the effectiveness and efficiency of program policies. Such improvement will depend on the time horizon of the analysis. About costs and failure modelling, there is a huge range of diverse approaches,
S tep 2: EFFICIENCY
analytical and empirical, related to other RA & MDT adapted to Warranty
Warranty Policy Risk-CostBenefit Analysis
fields. In order to carry out a Warranty Policy Risk-Cost-Benefit Analysis, such activity will depend of course on the
Figure 10. Second Step, proposed for the Warranty Efficiency
objective that the own model builder keeps in mind.
In figure 9, an integrated model for total warranty costs is presented. In any case (as here with the management of a warranty program), the problem is influenced by the information available. In addition to this, the complexity of the issue is usually high and considerations must be taken under certain assumptions in order, either to simplify the analytical resolution, or to reduce sometimes the computational needs.
3.3 Third Step: Warranty Program Assessment Once designed, planned and scheduled activities of the warranty program using the above described techniques, the performance of such tasks has to be evaluated and assessed. As a complement of the mentioned techniques, a study related to Reliability, Availability, Maintainability and Safety (RAMS analysis) takes its importance due to the huge amount of restrictions and conditions that any complex product, currently on the market, hold in itself. Its components or subsystems present ranges of potential modes of failure that must be considered from the initial state of design. Some standards (as the ISO 14224/2000) deal with this matter. In any case, the RAMS analysis gives an approached evaluation of the product behaviour when it will be in use. As a result of such analysis, one can obtain a deep knowledge about the product capacity to perform properly the functions expected from it, under established conditions and during a period of specific time. It is also possible to know in which degree a system or component can be used during a certain interval of time, or must be restored or substituted. In addition to this, this analysis takes into account the condition of the product to be protected against failures, mistakes, accidents, damages, or any other incident considered as not desirable. These
concepts are usually expressed in terms of probability and for their measurement it is taken into account the mechanisms and relationships between failure cause and effect. Due to the fact that, as mentioned, an aftersales support is frequently offered while the production line is still open (see figure 2), the purpose here is to improve the product engineering and manufacturing with the feedback of warranty program data. With the data gathered till now, a reliability assessment can highly influence in changes on the product design as it is shown in figure 11. DETAIL DESIGN - Com ponent reliability - Reliability developm ent - Constraints
RELIABILITY MODELS - Testing m odel - Assesm ent m odel
DECISIONS PROCESS
DATA - Vendor data - Test Data
PROTOTYPE - Reliability developm ent - Product im plications
Figure 11. Reliability assessment and the product development (Adapted from D. N. P. Murthy, W. R. Blischke, 2006)
With an adequate reliability and availability assessment, is possible to demonstrate in the first stages of the product, how requirements expressed in initial technical specifications can be incompatible or even impossible to accomplish for determined product configurations [V. González Díaz, et Al. (2009)]. If the product is already launched, this analysis can help to take quickly the necessary measures to correct and/or improve the product, foreseeing also probable claims from the users due to the real lack of reliability on the product, in comparison with the previous reliability, sold a priori. To complete this 3rd step about warranty program assessment is important to include a Life Cycle Cost Analysis, which calculates the cost of the product for its entire life. The typical analysis includes costs for planning, research and development, production, operation, warranty and disposal [C. Parra et Al. (2009)]. From the consumer’s point of view, the life cycle cost will suppose the acquisition costs, purchase price, costs of operation and maintenance, etc. That means, in general, the total cost of the item ownership.
In any case, the life cycle cost regarding warranty issues, is highly influenced on the values for reliability
S tep 3: AS S ES S MENT
and failure rate, cost of spares, repair times,
and
component
costs.
Life Cycle Cost Analysis
Normally, a low budget for product engineering leads to high warranty
Reliability, Availability, Maintenability and Safety
Figure 12. Third Step, proposed for the Warranty Program Assessment
costs in the future. Those customer complaints related to important or costly failures, should be soon attended and the failures fully analyzed to identify not only further tasks to proceed with the repair, but also preventive actions which can avoid or at least, to decrease future claims due to similar reasons. Therefore, this consideration involves performing a root cause failure analysis already included in step 1. An overall review of all the warranty complaints can show repetitive failures and trends related to vendor/buyer problems, quality issues, manufacturing conditions, product design, etc.
3.4 Fourth Step: Warranty Program Improvement As a result of the previous steps of this management process, a continuous improvement of the warranty program management is possible thanks to the application of emerging techniques and technologies in areas considered of higher impact. The implementation of new technologies to warranty brings with itself the introduction of the concept “E-Warranty”. As it is shown in figure 4, this concept is proposed as a component S tep 4: IMPROVEMENT
Six sigma
of the e-manufacturing, which takes Customer Relationship Management
an advantage from the emerging E-Technologies (E-Warranty)
information
and
communication
technologies, in order to implement a Figure 13. Fourth Step, proposed for the Warranty Improvement
cooperative and distributed multiuser environment.
Therefore, E-Warranty can be defined as a warranty program support which includes the resources, services and management necessary to enable proactive decision. This support not only includes etechnologies, but also e-warranty activities such as e-monitoring, e-diagnosis, e-prognosis... etc.
Together with the implementation of new technologies for a warranty program, it is crucial to involve the warranty technicians with the warranty improvement process, in order to reach a successful goal which supposes higher level of product quality and program effectiveness. Consequently, higher levels of knowledge, experience and training will be required. It is clear that one of the most important parts inside the management of a warranty program is the relationship with the client. The techniques that manage these relationships are usually considered part of an ERP system (Enterprise Resource Planning), and sometimes it is treated as a complementary part. The CRM (Customer Relationship Management) is used not only to define a strategy of business centred in the client, but also to include a group of applications useful to deal with data related to
CUSTOMER
clients, complaints and, in general, the commercial activity of a company.
COMMUNICATION CHANNELS
INVOLVED DEPARTMENTS
Web and Email
Aftersales
On Field Technicians
Management Board
Call Center
WARRANTY INFORMATION
Quality
Partners and Subcontractors
Engineering
E-Warranty System
Manufacturing
FRONT OFFICE
BACK OFFICE
Figure 14. Customer Relationship Management for the proposed framework
As mentioned, the CRM is used often as a module for the customers’ management inside ERP software. Originally, the CRM was more focused to marketing and commercial aspects. Nevertheless, a CRM module can be adapted for the warranty management, which should allow the company:
to identify products and services that clients require to be attended;
to optimize assistance times and information channels;
to identify clients' groups in order to develop warranty strategies;
to be aware about the current aftersales necessities of the clients;
to increase sales of the company together with the client's satisfaction;
among others.
The customer relationship management (just as part of an ERP or as a complementary system), includes operational areas and tasks that deal directly with the client (“front office”), and other ones more analytical where different parts of the company are closely involved (“back office”) representing the business intelligence, as it is shown in figure 14. The main part of any CRM strategy
will be the Data Base, which can provide very interesting information about complaints, repetitive failures, hidden defects, quantitative and qualitative analysis, statistical results etc.
To lubricate all this machinery, is necessary the set-up of programs to optimize the organizational efficiency, in this case focused on the warranty program management. For that purposes it is possible and interesting to adapt, for instance, concepts from the Total Productive Maintenance (TPM) philosophy. The TPM tries to achieve a continuous improvement applied in that case to a maintenance practice. This objective resides also in other methodologies like TQM (Total Objetive
Quality Management) or even the ISO 9000 which has been used here
Focus
as a base for the framework. In our case, and with the intention to go
Strong Point
beyond, many organizations are recently
implementing
a
new
Customer Satisfaction Process Improvement Committed Employees Effective Tools
Method
Leadership
management philosophy that can be
Support
Communication
Resources
Rewards
also very useful for the warranty management.
Figure 15. Integration of Total Quality Principles in 6 Sigma
The Six Sigma is a methodology which integrates the human factor with improvement tools, mainly statistical to engage the complex mechanisms inside a company. As it is known, Sigma in statistic means a dispersion measure (variability). This variability is considered as the main enemy of quality; therefore, 6-sigma proposes the following steps:
To select indicators or variables, which are critical for quality.
To take measures of these variables in order to compile real data of the current situation.
To detect the variation source of those interesting variables and their allowed tolerance.
To implement solutions.
To apply statistical controls that allows the long / middle term improvement.
The application of the 6-sigma philosophy supposes the necessity of real data and the use of a huge amount of variables. Therefore, this methodology combined with new e-technologies can bring very good results in the field of the warranty program management.
Business Profit
Customer Satisfaction Management Excelence
For the implementation of the 6-sigma, it is required a team dedicated full-time to such matters.
6 SIGMA
Regarding warranty issues, this team should be Objectives Decisions
Process Measure
Orientation to Customer
composed by middle managers, independents of aftersales, engineering, manufacturing or quality department, but establishing a management board who watch over the warranty matters dealing with the complaints from customers and/or to providers. Figure 16. Fundamental pillars of the 6-Sigma methodology
Similar to figure 1, the figure 17 illustrates the actual situation versus the desired one, regarding any business process and showing where warranty issues perform a crucial influence.
Actual process
MAINTENANCE ISSUES
WARRANTY ISSUES TO SUPPLIERS
Reprocess
A
Suppliers
B Checking
WARRANTY ISSUES FROM CUSTOMERS
Delay
C Checking
D Checking
Customers
Checking
Discard
Remake Complaint
Complaint
Desired process Suppliers
A
B
C
D
Figure 17. Actual vs. Desired business process and the impact of Warranty issues
Customers
4.
CONCLUSIONS
Currently, it is possible to find in the literature studies with very interesting contributions about models and frameworks related to the management of warranty programs [V. González Díaz et Al. (2009)]. As the business world is more and more competitive, only those new management philosophies can bring a difference. Therefore, the purpose here has been to adapt and to apply wellknown techniques (developed for other areas) to a field which was not yet in the focus of most of the executives.
S tep 1: EFFECTIVENES S
Criticality Analysis
Failure Root Cause Analysis
Six sigma
RA & MDT adapted to Warranty
Customer Relationship Management
Warranty Policy Risk-CostBenefit Analysis
E-Technologies (E-Warranty)
Life Cycle Cost Analysis
Step 2: EFFICIENCY
Step 4: IMPROVEMENT
Balance Score Card
Reliability, Availability, Maintenability and Safety
S tep 3: AS S ES S MENT
Figure 18. Proposed Framework for Warranty Program Management
The present paper has summarized the process (those series of stages) and the framework (the essential supporting structure) needed to manage a warranty program, suggesting methods to improve the program management and its decision making. In figure 18 is shown the complete framework proposed for the management of a warranty program, where the steps to follow, described along this paper, are shown together in a general overview. As mentioned, the suggested framework considers already developed techniques, classifying them according to their more suitable utilization within the warranty management process. The given ideas
and tools try to resolve problems and to understand easily what is happening in the field about warranty, applying for that purpose, some of the latest trends in business management and proposing new ones as the E-Warranty. Consequently, this paper also pretends to provide the reader with an upto-date review and citations of significant methods, techniques and technologies, to enable an organization the development of various warranty-related functions, allowing them to face the complexities typical in today’s manufacturing and service environments.
5.
BIBLIOGRAPHY
[1] A. Crespo, P. Moreu, J. Gómez, C. Parra, V. González Díaz. “The maintenance management framework: A practical view to maintenance management.” 2009 Taylor & Francis Group, London, ISBN 978-0-415-48513-5. Pag. 669674. [2] A. Crespo Marquez. “The maintenance management framework: models and methods for complex systems maintenance”. 2007. Springer-Verlag London Limited. ISBN-13: 9781846288203 [3] D. N. P. Murthy, W. R. Blischke. “Warranty management and product manufacture”. Springer-Verlag London Limited, 2006. ISBN 1852339330 [4] V. González Díaz, A. Crespo Márquez. “Case study: Warranty costs estimation according to a defined lifetime distribution of deliverables”, -not published yet- EURENSEAM WCEAM 2009, Athens. [5] L. Mihok. “Quality management systems – New approach by ISO 9000/2000”. Metalurgija 43 (2004) 3, Pp. 193-198. ISSN 0543-5846. [6] EN ISO 9000/2000 standards. “Petroleum, petrochemical and natural gas industries — Collection and exchange of reliability and maintenance data for equipment”. European Committee for Standardization, Brussels. [7] Koç M, Ni J, Lee J, Bandyopadhyay P. “Introduction of e-manufacturing” 2003. In: 31st North American Manufacturing Research Conference (NAMRC), Hamilton, Canada. [8] J. Gómez, A. Crespo, P. Moreu, C. Parra, V. González Díaz. “Outsourcing maintenance in services providers.” 2009 Taylor & Francis Group, London, ISBN 978-0-415-48513-5. Pag. 829-837. [9] K. Lyons, D.N.P. Murthy. “Warranty and manufacturing, integrated optimal modelling”. M.A. Rahim, M. Ben-Daya (Eds.), Production Planning, Inventory, Quality and Maintenance, Kluwer Academic Publishers, New York, 2001, pp. 287–322. [10] ISO/DIS 14224, ISO TC 67/SC /WG 4. “Petroleum, petrochemical and natural gas industries - Collection and exchange of reliability and maintenance data for equipment”, 2004 Standards Norway. [11] V. González Díaz, A. Crespo, P. Moreu, J. Gómez, C. Parra. “Availability and reliability assessment of industrial complex systems: A practical view applied on a bioethanol plant simulation”, 2009 Taylor & Francis Group, London, ISBN 978-0-415-48513-5. Pag. 687-695. [12] C. Parra, A. Crespo, P. Moreu, J. Gómez & V. González Díaz. “Non-homogeneous Poisson Process (NHPP), stochastic model applied to evaluate the economic impact of the failure in the Life Cycle Cost Analysis (LCCA).” 2009 Taylor & Francis Group, London, ISBN 978-0-415-48513-5. Pag. 929-939. [13] V. González Díaz, J.F. Gómez, M. López, A. Crespo. “Warranty cost models State-of-Art: A practical review to the framework of warranty cost management”, -not published yet- ESREL 2009, Prague.
