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Performance Measurement Framework for Product-Service System Development: A Balanced Scorecard Approach
No full textThe Product-Service System (PSS) paradigm is recognized as a means for
companies to increase the value perceived by the customers, thus gaining
competitive advantage beyond traditional ‘pure product’ offerings. Researches
have shown the necessity to rethink design processes in a PSS context, in order
to drive the successful integration of product and service features in early
design phases. In the last few years, several new approaches have been
proposed, however little attention has been paid on how to translate these
approaches into action and on how to evaluate their performances and
effectiveness. This paper proposes a framework for analysing the performances
in PSS development process using a Balanced Scorecard approach, as a tool to
guide the implementation and the evaluation of new methods and tools in the
early design phases. The paper starts with discussing the main challenges
encountered when designing PSS, and then, adopting an aerospace industry as an
example, to propose an application of the Balance Scorecard for the
implementation and measurement of PSS development. Finally, the main pros and
cons are discussed in relation to strengths and weaknesses of using balanced
scorecard in PSS development. The framework developed in this paper can provide
a useful guidance for the managers in measuring the performances of the PSS
development process
Hållbarhets- och kostnadsanalys av energibärare för bussar i medelstora svenska städer: SLCA, LCA, LCC jämförelseanalys av biogas, biodiesel, diesel, elhybrid, laddhybrid och eldrift för kollektivtrafikbussar i Karlskrona, Jönköping och Sundsvall
No full textDagens vägtransporter hjälper människor att berika sina liv genom möjlighet
till snabba, flexibla och bekväma resor, samt förbättrad tillgång till varor
och tjänster. Dock bidrar dagens vägtransporter till hållbarhets- problem och
andra problem såsom klimatpåverkan, buller, barriärer i landskapet och olyckor
med dödlig utgång. Det svenska samhället har under de senaste decennierna
börjat uppmärksamma de stora hållbarhets- utmaningarna världen står inför.
Regeringen har satt mål för växthusgasneutralitet år 2050 och en fossil-
oberoende fordonsflotta 2030, samt andra mer närtida miljömål. Tyvärr pekar
bl.a. indikatorer i miljömåls- portalen på att de flesta av dessa mål inte
kommer att uppfyllas. Samtidigt kommer bebyggda områden att förtätas och
vägtransporter förväntas öka. Vägtrafikens negativa påverkan på människors
hälsa kommer därför att öka om ingen förändring görs, framförallt i stads-
miljö. För att bidra till hållbar utveckling behöver utsläpp från lastbilar,
bussar och personbilar minska.
Regionala och kommunala organisationer kan bidra till omställningen till
hållbarhet bl.a. genom ökade krav på lokaltrafikens fordon så att de blir mer
energieffektiva, samt avger mindre luftföroreningar och buller. Bussar med
elektrifierad drivlina, som laddas med förnyelsebar ny el, är i dagsläget ett
lovande alternativ för en sådan förändring. Ett högt inköpspris för eldrivna
fordon är i dagsläget ett hinder i upphandling för kollektivtrafik, men det kan
komma att sjunka med ökade försäljnings- volymer och teknisk utveckling,
framförallt beträffande batterier. Tidigare studier visar på fördelar för
eldrift av bussar i storstadsmiljöer (Stockholm, Göteborg och Malmö). Denna
studie syftar till att utreda hållbarhets- implikationer och lönsamheten i att
använda bussar med någon form av eldrift i kollektivtrafiken i mellan- stora
städer jämfört med dagens bussar som drivs med förbränningsmotorer. Med hjälp
av Blekingetrafiken, Jönköpings Länstrafik, Västernorrlands kollektivtrafik-
myndighet och Volvo Technology Corporation har författarna gjort fallstudier på
utvalda stadsbusslinjer i Karlskrona, Jönköping och Sundsvall. Studien
tillämpar metodik för strategisk hållbar utveckling som utvecklas i en
internationell vetenskaplig samverkansprocess med Blekinge Tekniska Högskola
som koordinerande nod. För att bl.a. undvika suboptimeringar ur ett helhets-
perspektiv (förbättringar i en fas som kan ge fler och större problem i andra
faser, samt hindra global hållbar utveckling) används strategisk
livscykelanalys (SLCA) för att identifiera särskilda analysområden, livscykel-
analys (LCA) för kvantifiering av emissioner, och livs- cykelkostnadsanalys
(LCC) för beräkning av lönsamhet och konkurrenskraft.
Beräkningar baseras på tidigare studier och dessa kom- pletteras och verifieras
genom simulering av energi- användning för respektive linje. Författarna har
valt att studera energibärare då dessa utgör största skillnaden mellan
traditionella fossildrivna bussar och de som drivs med el i någon form. Studien
utgår från diesel med 5 % FAME/RME och lokalt producerad förnybar ny el från
källor som per år ger mer till nätet än vad som tas ut, exempelvis genom s.k.
vindkraftsandelar. Eldrift förekommer i tre varianter varav två är hybrider.
Primär drivkälla för elhybrid är förbränningsmotorn, vilket förväntas spara i
snitt 33 % energi gentemot en dieseldriven buss. Laddhybrid drivs primärt av
elmotor med batterier (laddas internt och externt) samt i andra hand av
förbränningsmotor, men kan styras till att bli 100 % eldriven. För att utreda
lämpligt biobränsle för dessa studeras lokalt framställd biogas ur
hushållsavfall och biodiesel (RME) från lokalt odlad raps. Det senare har ur
tillgänglighetssynpunkt valts som bränsle till elhybrid och laddhybrid i denna
studie.
Slutsatserna från studien är att bussar för stadstrafik i medelstora städer som
primärt drivs av el (från lokala vindkraftsandelar) jämfört med dieseldrift
är...
... tydligt bättre i alla livscykelfaser beträffande energi- effektivisering
och emissioner bidragande till växt- huseffekt, försurning, övergödning,
skapande av marknära ozon, och partiklar. Detta trots nyttjande av knappa
material som Litium i batterier. Det finns också potential till radikal
minskning av ljudnivån på bullriga platser. En elhybrid- eller laddhybrid- buss
bör ur miljösynpunkt drivas med biogas.
... enligt ekonomisk nuvärdeskalkyl ekonomiskt kon- kurrenskraftiga när
anskaffning av laddinfrastruktur (en extra snabbladdare), fordon, samt
underhålls- kostnader (med 1 batteribyte), energianvändning (årlig prisökning
med 6 %) inkluderas. Elhybrid är 7 %, laddhybrid 18 % och helt eldriven buss 24
% billigare än dieseldrift i Karlskrona (linje 1/7). Lokalt producerad förnybar
ny el ger dessutom nya lokala och regionala arbetstillfällen, vilket kan
värderas mer än det gjorts i denna studie.
... om något år ekonomiskt lönsamma för linjer vars sträckning kräver mer än 5
snabbladdningsstationer.
Resultaten visar på vissa skillnader mellan de studerade städerna, som till
största del beror på utnyttjandegraden av bussar, linjernas karaktär, samt
stadens storlek och ventilationsfaktorn. Förbättringar ur miljösynpunkt jämfört
med dieseldrift är ganska lika i de studerade städerna, men
besparingspotentialen (i kronor) för elhybrid-, laddhybrid och el-drift är
störst i Karlskrona
Analyzing the concept of planetary boundaries from a strategic sustainability perspective: How does humanity avoid tipping the planet?
No full textRecently, an approach for global sustainability, the planetary-boundary
approach (PBA), has been proposed, which combines the concept of tipping points
with global-scale sustainability indicators. The PBA could represent a
significant step forward in monitoring and managing known and suspected global
sustainability criteria. However, as the authors of the PBA describe, the
approach faces numerous and fundamental challenges that must be addressed,
including successful identification of key global sustainability metrics and
their tipping points, as well as the coordination of systemic individual and
institutional actions that are required to address the sustainability
challenges highlighted. We apply a previously published framework for
systematic and strategic development toward a robust basic definition of
sustainability, i.e., the framework for strategic sustainable development
(FSSD), to improve and inform the PBA. The FSSD includes basic principles for
sustainability, and logical guidelines for how to approach their fulfillment.
It is aimed at preventing unsustainable behavior at both the micro, e.g.,
individual firm, and macro, i.e., global, levels, even when specific global
sustainability symptoms and metrics are not yet well understood or even known.
Whereas the PBA seeks to estimate how far the biosphere can be driven away from
a "normal" or "natural" state before tipping points are reached, because of
ongoing violations of basic sustainability principles, the FSSD allows for
individual planners to move systematically toward sustainability before all
impacts from not doing so, or their respective tipping points, are known.
Critical weaknesses in the PBA can, thus, be overcome by a combined approach,
significantly increasing both the applicability and efficacy of the PBA, as
well as informing strategies developed in line with the FSSD, e.g., by
providing a "global warning system" to help prioritize strategic actions
highlighted by the FSSD. Thus, although ongoing monitoring of known and
suspected global sustainability metrics and their possible tipping points is a
critical part of the evolving sustainability landscape, effective and timely
utilization of planetary-boundary information on multiple scales requires
coupling to a strategic approach that makes the underlying sustainability
principles explicit and includes strategic guidelines to approach them. Outside
of such a rigorous and systems-based context, the PBA, even given its global
scale, risks leading individual organizations or planners to (i) focus on
"shares" of, e.g., pollution within the PBs and negotiations to get as high
proportion of such as possible, and/or (ii) awaiting data on PBs when such do
not yet exist before they act, and/or (iii) find it difficult to manage
uncertainties of the data once such have arrived. If global sustainability
problems are to be solved, it is important that each actor recognizes the
benefits, not the least self-benefits, of designing and executing strategies
toward a principled and scientifically robust definition of sustainability.
This claim is not only based on theoretical reasoning. A growing number of
sectors, businesses, and municipalities/cities around the world are already
doing it, i.e., not estimating "allowed" shares of, say fossil CO2 emissions,
but gradually moving away from unsustainable use of fossil fuels and other
unsustainable practices altogether
A Simple Time-based Threshold Strategy for Dynamic Spectrum Access
No full textIn dynamic spectrum access networks, the unused licensed spectrum of primary
users (PU) is opened to unlicensed secondary user (SU) for improving spectrum
efficiency.
The problem we study in this paper is to maximize the SU throughput while
guaranteeing PU performance.
We design a simple time-based threshold strategy to maximize the SU throughput
while guaranteeing the PU performance by learning directly from the interaction
with PU environment. At a given time, the SU decides if it should transmit and
if so to protect the PU performance.
It is observed that such strategies perform closely to the strategy optimized
based on prior knowledge about PU traffic models. Simulations are used for
performance evaluation
Optimal computer crash performance precaution
No full textFor a parallel computer system withmidentical computers, we study optimal
performance precaution for one possible computer crash. We want to calculate
the cost of crash precaution in the case of no crash. We thus define a
tolerance level r meaning that we only tolerate that the completion time of a
parallel program after a crash is at most a factor r + 1 larger than if we use
optimal allocation on m - 1 computers. This is an r-dependent restriction of
the set of allocations of a program. Then, what is the worst-case ratio of the
optimal r-dependent completion time in the case of no crash and the
unrestricted optimal completion time of the same parallel program? We denote
the maximal ratio of completion times f(r, m) - i.e., the ratio for worst-case
programs. In the paper we establish upper and lower bounds of the worst-case
cost function f(r, m) and characterize worst-case programs
Teaching Modeling—An Initial Classification of Related Issues
No full textModeling is an important skill needed in both science and engineering domains.
In software engineering, in particular, models are ubiquitous artefacts.
The development, manipulation and understanding of models is therefore an
important learning objective. The paper presents the initial results of an
attempt that has been carried out in order to classify issues related to the
teaching and learning of modeling
Distributed Thermal Storage Using Multi-Agent Systems
No full textThermal storage is an essential concept within many energy systems. Such
storage is generally used in order to smooth out the time lag between the
acquisition and the use of energy, for example by using heat water tanks within
heating systems. In this work we use a multi-agent system in order to maintain
and operate distributed thermal storage among a large group of buildings in a
district heating system. There are several financial and environmental benefits
of using such a system, such as avoiding peak load production, optimizing
combined heat and power strategies and achieving general energy efficiency
within the network.
Normally a district heating system is purely demand driven, resulting in poor
operational characteristics on a system wide scale. However, by using the
thermal inertia of buildings it is possible to manage and coordinate the heat
load among a large group of buildings in order to implement supply driven
operational strategies. This results in increased possibilities to optimize the
production mix from financial and environmental aspects.
In this paper we present a multi-agent system which combines the thermal
storage capacities within buildings in relation to production optimization
strategies. The agent system consist of producer agents responsible for valuing
the
necessary heat load management, consumer agents managing the quality of service
in individual buildings while consenting to participate in heat load management
and a market agent acting as a mediating layer between the producer and
consumer agents. The market agent uses an auction-like process in order to
coordinate the heat load management among the consumer agents, while the
producer agents use load forecasting in order to evaluate the need for heat
load management at any given point in time. A consumer agent uses continues
feedback regarding indoor climate in order to uphold quality of service while
par-
ticipating in heat load management.
Real-time data from a district heating system in Sweden is used in order to
evaluate the agent system in relation to operational peak load management. The
results show clear financial and environmental gains for the producer as well as
participating consumer
SAR Imaging in Ground Plane Using Fast Backprojection for Mono- and Bistatic Cases
No full textThe paper discusses the possibilities to reconstruct an illuminated Synthetic
Aperture Radar (SAR) scene in a ground plane instead of a slant-range plane
using Fast Backprojection (FBP) algorithm. Hence, two methods to reconstruct a
SAR scene in a ground plane are introduced in this paper. The methods are then
considered to be extended for bistatic cases where the formation of a SAR scene
in a ground plane is highly recommended. The proposals are examined with
simulated SAR data and the simulation results indicate that rebuilding a SAR
scene in a ground plane using FBP is possible
On Synthetic Aperture Radar Spatial Azimuth and Range Resolution Equations
No full textThis paper discusses spatial resolutions for narrowband narrowbeam (NB)
synthetic aperture radar (SAR) as well as for ultrawideband ultrawidebeam (UWB)
SAR. The similarity and difference between the impulse response function in NB
SAR imaging (IRF-NSAR) - sinc function - and the impulse response function in
UWB SAR imaging (IRF-USAR) is investigated and the result of this investigation
shows that in the intensity interval from −6 dB to 0 dB, the behavior of
IRF-NSAR and IRF-USAR in azimuth and range are similar. This is the basis for a
derivation of new spatial resolution equations for UWB SAR based on −3 dB width
or half power beamwidth (HPBW). The investigated result also shows that there
exists the so-called HPBW narrowing/broadening factor in an IRF-USAR
On Routing in Cognitive Radio Networks
No full textAbstract—Cognitive Radio Networks (CRNs) are expected toaddress and to resolve
important technological and operational challenges of future networks, such as
Dynamic Spectrum Access (DSA), routing in heterogeneous networks and provision
of
Quality of Experience (QoE) for different applications. Accordingly, a number
of new terminal and network functionalities are required to solve the technical
problems and to provide efficient management of CRNs. The paper advances a new
solution for routing in CRNs, providing communication between Secondary Users
(SUs) occupying different so-called Spectrum
Opportunities (SOPs), i.e., portions of spectrum not occupied by Primary Users
(PUs). This entails solving a complex process composed by two fundamental
elements. These elements are multi-constraint routing and multi-dimensional
adaptation for multiple cognitive radio dimensions like space, frequency, power
and time. The goal of the paper is to develop optimization algorithms necessary
to provide end-to-end (e2e) routing paths for communication between SUs with
associated QoE demands