315 research outputs found
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Lean in healthcare: The unfilled promise?
In an effort to improve operational efficiency, healthcare services around the world have adopted process improvement methodologies from the manufacturing sector, such as Lean Production. In this paper we report on four multi-level case studies of the implementation of Lean in the English NHS. Our results show that this generally involves the application of specific Lean âtoolsâ, such as âkaizen blitzâ and ârapid improvement eventsâ, which tend to produce small-scale and localised productivity gains. Although this suggests that Lean might not currently deliver the efficiency improvements desired in policy, the evolution of Lean in the manufacturing sector also reveals this initial focus on the âtool levelâ. In moving to a more system-wide approach, however, we identify significant contextual differences between healthcare and manufacturing that result in two critical breaches of the assumptions behind Lean. First, the customer and commissioner in the private sector are the one and the same, which is essential in determining âcustomer valueâ that drives process improvement activities. Second, healthcare is predominantly designed to be capacity-led, and hence there is limited ability to influence demand or make full use of freed-up resources. What is different about this research is that these breaches can be regarded as not being primarily âprofessionalâ in origin but actually more âorganisationalâ and âmanagerialâ and, if not addressed could severely constrain Leanâs impact on healthcare productivity at the systems level
Evidence for saturation of channel transmission from conductance fluctuations in atomic-size point contacts
The conductance of atomic size contacts has a small, random, voltage
dependent component analogous to conductance fluctuations observed in diffusive
wires (UCF). A new effect is observed in gold contacts, consisting of a marked
suppression of these fluctuations when the conductance of the contact is close
to integer multiples of the conductance quantum. Using a model based on the
Landauer-Buettiker formalism we interpret this effect as evidence that the
conductance tends to be built up from fully transmitted (i.e., saturated)
channels plus a single, which is partially transmitted.Comment: An error in Eq.(2) was corrected, where a square root was added to
the factor (1-cos(gamma)). This results in a revised estimate for the mean
free path of 5 nm, which is now fully consistent with the estimates from the
series resistance and the thermopowe
From lean production to Industrie 4.0: More autonomy for employees?
The article examines the relationship between lean production and Industrie 4.0 focusing on the question of autonomy in the work process. In contrast to the claim made by official Industrie 4.0 concepts that the autonomy of the employees would increase, we see in the current implementation projects a tendency towards greater standardization and control of work. This is in continuity with concepts of lean production, but neglects the participation-oriented elements of lean production such as teamwork and shop-floor-based improvement activities. Our argument is developed by analyzing practical examples from three relevant fields (digital assistance systems, data-based process management, modular assembly). The conclusions of this article also discuss the extent to which the concept of individual autonomy is suitable for the assessment of Industrie 4.0 concepts, given the high levels of interdependence already achieved in production processes
Towards eco-efficient lean production systems
Lean Production has proved itself a worthwhile production strategy in many
distinct industries across all regions of the planet by achieving higher levels of
production efficiency. Several authors identified that Lean inadvertently has
had significant environmental gains. Such achievements are considered of
special relevance in a global and highly competitive economy which is
progressively both tied-up and driven by an environmental agenda. The main
goal of the present study is to enlighten the contribution of Lean for achieving
a better environmental performance of production systems and identify this as
an emergent business model for supporting eco-efficiency
Effect of quantum interference in the nonlinear conductance of microconstrictions
The influence of the interference of electron waves, which were scattered by
single impurities, on nonlinear quantum conductance of metallic
microconstrictions (as was recently investigated experimentally) is studied
theoretically. The dependence of the interference pattern in the conductance
on the contact diameter and the spatial distribution of impurities is
analyzed. It is shown that the amplitude of conductance oscillation is strongly
depended on the position of impurities inside the constriction.Comment: 6 pages, 4 figures, To appear in PR
Andreev Reflection In Ferromagnet-Superconductor Junctions
The transport properties of a ferromagnet-superconductor (FS) junction are
studied in a scattering formulation. Andreev reflection at the FS interface is
strongly affected by the exchange interaction in the ferromagnet. The
conductance G_FS of a ballistic point contact between F and S can be both
larger or smaller than the value G_FN with the superconductor in the normal
state, depending on the ratio of the exchange and Fermi energies. If the
ferromagnet contains a tunnel barrier (I), the conductance G_FIFS exhibits
resonances which do not vanish in linear response -- in contrast to the Tomasch
oscillations for non-ferromagnetic materials.Comment: 8 pages, RevTeX v3.0, including 3 encapsulated postscript figures;
[2017: figures included in text
Ballistic electron transport through magnetic domain walls
Electron transport limited by the rotating exchange-potential of domain walls
is calculated in the ballistic limit for the itinerant ferromagnets Fe, Co, and
Ni. When realistic band structures are used, the domain wall magnetoresistance
is enhanced by orders of magnitude compared to the results for previously
studied two-band models. Increasing the pitch of a domain wall by confinement
in a nano-structured point contact is predicted to give rise to a strongly
enhanced magnetoresistance.Comment: 4 pages, 2 figures; to appear in PRB as a brief repor
Economies of collaboration in build-to-model operations
This is the final version. Available from the publisher via the DOI in this record.The direct-from-model and tool-less manufacturing process of 3D printing (3DP) embodies a general-purpose technology, facilitating capacity sharing and outsourcing. Starting from a case study of a 3DP company (Shapeways) and a new market entrant (Panalpina), we develop dynamic practices for partial outsourcing in build-to-model manufacturing. We propose a new outsourcing scheme, bidirectional partial outsourcing (BPO), where 3D printers share capacity by alternating between the role of outsourcer and subcontractor based on need. Coupled with order book smoothing (OBS), where orders are released gradually to production, this provides 3D printers with two distinct ways to manage demand variability. By combining demand and cost field data with an analytical model, we find that BPO improves 3DP cost efficiency and delivery performance as the number of 3DP firms in the network increases. OBS is sufficient for an established 3D printer when alternatives to in-house manufacturing are few, or of limited capacity. Nevertheless, OBS comes at the cost of reduced responsiveness, whereas BPO shifts the cost and delivery performance frontier. Our analysis shows how BPO combined with OBS makes 3DP companies more resilient to downward movements in both demand and price levels.Innovate UKEngineering and Physical Sciences Research Council (EPSRC
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