Salvador F. Capuz-Rizo

Modularity and Ease of Disassembly: Study of Electrical and Electronic Equipment

A common recommendation when designing for disassembly is to develop more modular products. The common belief is that an increase in modularity will systematically reduce the time required in order to disassemble the product, reducing the cost of the process. This paper studies the statistical relationship between these two concepts by comparing 15 different electrical products. Modularity and disassembly performance are assessed by different indicators each and their correlation is analyzed. The results show that the aforementioned relationship cannot be statistically proven and, for some of the cases, even inverse correlation is found. Factors such as product structure or selected end-of-life strategy are more important than modularity in end-of-life performance. Systematic modularization can even result in products with a worse behavior: For most electrical equipment, generating modules from a functional or manufacturing point of view will most probably result in worse end-of-life performance. It is only for modules with very specific properties that performance can be guaranteed.

Estudio de la Incertidumbre en la Programación de Actividades usando la Matriz de Estructura Dependiente

A study about the effect of uncertainty on the planning of project activities using the dependency structure matrix (DSM) and grey theory. The grey theory is applied to represent the uncertainty in estimating project extension. As a result, the equations to determine the grey conventional time, the grey normal time and the grey normal time with natural overlap were developed. Based on the case studies it is concluded that the application of the grey theory to the DSM allows: considering the uncertainty in project planning; ii) identifying the most critical stages; iii) analyzing the effect of the uncertainty of each stage in the total project duration; and iv) comparing different programming strategies.

Organizational life cycle assessment: suitability for higher education institutions with environmental management systems

PurposeThe purpose of this study is to analyze the suitability of organizational life cycle assessments (O-LCAs) for higher education institutions (HEIs) with special attention to the benefits and particularities of those adopting environmental management systems (EMSs) verified according to Environmental Management and Audit Scheme (EMAS).MethodsA thorough analysis following ISO/TS 14072 and UNEP Guidance was carried out using the Universitat Politècnica de València (UPV) EMS verified by the EMAS for guiding principles to develop the methodological proposal. The self-sufficiency of UPV EMS for developing an O-LCA was tested at the university pilot unit. The four steps of the O-LCA were applied to the pilot.Results and discussionA reporting organization, the organization to be studied (boundaries and scope), was defined in consideration of the environmental units (EU) of the EMS. Operational control was selected as a consolidation method. Reporting flows and system boundaries are also discussed. A three-scope scheme of the GHG protocol is introduced and combined with the ISO 14072 boundary definition to support better alignment with the HEI structure. For the life cycle inventory analysis, a mechanism for identifying activities and processes as well as their material and energy flows is proposed in consideration of the particularities of HEIs. A procedure for the prioritization of data collection efforts and cutoffs was developed. The procedure integrates current EMAS actions based on the significance of environmental aspects combined with the influence of reporting organizations under their control. Impact categories focus on midpoint indicators along with an additional inventory level indicator as part of the life cycle impact assessment (LCIA). Unfortunately, due to a lack of quality data available, LCIA can only be assessed in part with little interest in outcomes. Partial results are presented.ConclusionsAn EMS verified by EMAS is proven to be useful in the assessment of O-LCA for HEIs. However, EMAS requirements do not ensure the availability of all data needed to develop an O-LCA. An accounting system should complement a lack of data if it is properly structured. Considerable efforts are required to obtain an accurate result. EMS and the accounting system may be able to provide information that supports an O-LCA approach based on a coherent prioritization of data collection efforts and cutoff procedures along with a set of justified impact category indicators. Overall, organization managers must be in favor of such an assessment to meet the requirements of successful implementation.

Evaluation of Project Duration Uncertainty using the Dependency Structure Matrix and Monte Carlo Simulations

The sequence of tasks is vital to the development of any project. The order of tasks is influenced by the information flow among them. The dependency structure matrix (DSM) can be used to model information flow. However, the information used by the DSM, including task duration, time required for communication, and task overlap, can have uncertain values. The aim of this paper is to analyze the effect of uncertainty on the scheduling of tasks using the DSM. Monte Carlo Simulation is applied to represent uncertainty in time estimates for projects using DSM. Conventional project duration, normal project duration with communication times, and normal project duration containing natural overlapping were considered for project time estimations. Several distribution functions were used to represent the uncertainty. It is concluded that project duration has normal distribution behavior that is independent of the type of input parameter distribution functions; that mean values of the input parameters give a good estimation of mean project duration; that interval and inner interval arithmetic give overestimation and underestimation of project duration times respectively.

Identificación de etapas y materiales de mayor impacto en el ciclo de vida del calzado

espanolLa repercusion de los impactos al medio ambiente ocasionado por la actividad humana, afecta a todas las actividades productivas y comerciales que sustentan el dia a dia. Los productos de consumo masivo como el calzado, provocan grandes impactos de acuerdo a los materiales y procesos usados para su fabricacion. Este trabajo de revision y analisis, tiene por objetivo conocer cuales son las etapas y materiales que provocan mayores impactos al medio ambiente, centrado en el calzado de piel. Los resultados demuestran que distintos autores llegan a resultados similares en cuanto a etapas y materiales de mayor impacto. Lo cual permite tomar medidas para revertir esta situacion, asi como canalizar los esfuerzos de investigacion en los procesos de curtido. EnglishThe environmental impacts caused by human activity, affects all productive and commercial activities that support the day to day. The products of massive consume such as footwear drive large impacts according to the materials and processes used for their manufacture. This paper present a literature review with the main aim to identify which are the phases and materials that cause greater environmental impacts to the environment, focusing on leather shoes. The results demonstrate that different authors reach similar results in terms of phases and high impact materials. The results permit change the current way of action and to focus the main efforts of research on tanning process.