A Decision-Analytic System Concept Selection for a Public Project

2008 ◽  
Vol 130 (11) ◽  
Author(s):  
Shun Takai ◽  
Kosuke Ishii

This paper presents a decision-analytic system concept selection for a public project. In the proposed approach, the decision-maker (engineer) chooses a system concept and requests a budget for building the system. The unique customer (government) decides whether to approve the project but also has the option to cancel the project if the cost of the project exceeds the budget. Thus, at the time of system concept selection, the cost of the system, the government’s criterion to approve the project, and its criterion to continue/cancel the project when the cost exceeds the budget are modeled as uncertainties. To model the uncertainty of project continuation, the engineer assumes that the government’s criterion to continue/cancel the project is a linear combination of its initial criterion to approve the project and the budget. By analyzing the government’s option to cancel the project, the engineer can optimize his or her choice of a system concept (technology and target system requirements) and budget.

2016 ◽  
Vol 10 (10) ◽  
pp. 133
Author(s):  
Mohammad Ali Nasiri Khalili ◽  
Mostafa Kafaei Razavi ◽  
Morteza Kafaee Razavi

Items supplies planning of a logistic system is one of the major issue in operations research. In this article the aim is to determine how much of each item per month from each supplier logistics system requirements must be provided. To do this, a novel multi objective mixed integer programming mathematical model is offered for the first time. Since in logistics system, delivery on time is very important, the first objective is minimization of time in delivery on time costs (including lack and maintenance costs) and the cost of purchasing logistics system. The second objective function is minimization of the transportation supplier costs. Solving the mathematical model shows how to use the Multiple Objective Decision Making (MODM) can provide the ensuring policy and transportation logistics needed items. This model is solved with CPLEX and computational results show the effectiveness of the proposed model.


2014 ◽  
Author(s):  
M. Harbison ◽  
W. Koon ◽  
V. Smith ◽  
P. Haymon ◽  
D. Niole ◽  
...  

As a result of enhanced performance and mission requirements for Navy ships, ship design has dramatically increased the use of higher strength, lightweight steels and various local reinforcements, e.g., deck inserts, ring stiffeners, etc., in foundation designs to satisfy the design requirements for supporting machinery, consoles, and weapon systems among others. In additional to operational loading requirements, most of these foundations must also be designed to satisfy shock, vibration and other combat system requirements. While the same piece of equipment may be used in other ship contracts, the foundations are uniquely designed and require a separate analysis and drawing package. Computer modeling and Finite Element Analysis (FEA) have helped reduce the labor required to analyze foundations, but the high number of “unique” foundations as well as changes which necessitate a new analysis still create a large workload for engineers. This is further compounded by increased costs in production due to greater numbers of unique parts and materials that must be marked, stored, and retrieved later for fabrication. This goal of this project was to determine the cost-savings potential of leveraging past foundations work in designing, analyzing, and drawing foundations in the future. By the project’s conclusion Ingalls will have created a database for rapid access to previously-generated foundation information, the framework of which will be publicly available for all shipyards to populate with their own foundation information.


Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-20
Author(s):  
Paulo A. M. Barbosa ◽  
Plácido R. Pinheiro ◽  
Francisca R. V. Silveira ◽  
Marum Simão Filho

During the software development process, the decision maker (DM) must master many variables inherent in this process. Software releases represent the order in which a set of requirements is implemented and delivered to the customer. Structuring and enumerating a set of releases with prioritized requirements represents a challenging task because the requirements contain their characteristics, such as technical precedence, the cost required for implementation, the importance that one or more customers add to the requirement, among other factors. To facilitate this work of selection and prioritization of releases, the decision maker may adopt some support tools. One field of study already known to solve this type of problem is the Search-Based Software Engineering (SBSE) that uses metaheuristics as a means to find reasonable solutions taking into account a set of well-defined objectives and constraints. In this paper, we seek to increase the possibilities of solving the Next Release Problem using the methods available in Verbal Decision Analysis (VDA). We generate a problem and submit it so that the VDA and SBSE methods try to resolve it. To validate this research, we compared the results obtained through VDA and compared with the SBSE results. We present and discuss the results in the respective sections.


Author(s):  
K. Maddulapalli ◽  
S. Azarm ◽  
A. Boyars

We present an automated method to aid a Decision Maker (DM) in selecting the ‘most preferred’ from a set of design alternatives. The method assumes that the DM’s preferences reflect an implicit value function that is quasi-concave. The method is iterative, using three approaches in sequence to eliminate lower-value alternatives at each trial design. The method is interactive, with the DM stating preferences in the form of attribute tradeoffs at each trial design. We present an approach for finding a new trial design at each iteration. We provide an example, the design selection for a cordless electric drill, to demonstrate the method.


Author(s):  
Arvind Keprate ◽  
R. M. Chandima Ratnayake

Selecting a riser concept for FPSOs stationed in deep water has posed challenges, due to the high hydrostatic pressure and large vessel payload. One of the major factors governing the riser concept selection for deepwater FPSOs is the geographical location and weather conditions prevalent in the region. For example, the free hanging flexible riser has been mostly used in the moderate environments of offshore Brazil, while concepts like the SCR and Hybrid Riser Tower (HRT) are dominant in the calm weather conditions of the West of Africa (WoA). Selecting a riser concept for an FPSO stationed in harsh weather conditions like those of the Northern Norwegian Sea is a daunting task. This is due to the large vessel offsets and dynamics, which are directly transferred along the riser’s length to its base, thereby causing considerable fatigue damage to the riser. The main aim of this paper is to recommend a suitable riser concept, which may be hooked to an internal turret moored FPSO stationed in water of 1500m depth and in the harsh environmental conditions of the Northern Norwegian Sea. The recommendations are based on the literature review and the case study performed in the manuscript. On the basis of the literature review, a lazy wave configuration of flexible riser and Steel Lazy Wave Riser (SLWR) has been considered as a viable riser concept. Thereafter, a case study is performed to compare the two riser concepts, on the basis of vessel payload, fabrication cost and installation cost.


2016 ◽  
Vol 88 (3) ◽  
pp. 458-470 ◽  
Author(s):  
Alena Probst ◽  
Graciela González Peytaví ◽  
Bernd Eissfeller ◽  
Roger Förstner

Author(s):  
Daniel J Tobiansky ◽  
Kira M Long ◽  
Jordan E Hamden ◽  
Jeffrey D Brawn ◽  
Matthew J Fuxjager

Abstract Many animal species have evolved extreme behaviors requiring them to engage in repeated high-impact collisions. These behaviors include mating displays like headbutting in sheep and drumming in woodpeckers. To our knowledge, these taxa do not experience any notable acute head trauma, even though the deceleration forces would cause traumatic brain injury in most animals. Previous research has focused on skeletomuscular morphology, biomechanics, and material properties in an attempt to explain how animals moderate these high-impact forces. However, many of these behaviors are understudied, and most morphological or computational studies make assumptions about the behavior without accounting for the physiology of an organism. Studying neurophysiological and immune adaptations that co-vary with these behaviors can highlight unique or synergistic solutions to seemingly deleterious behavioral displays. Here, we argue that selection for repeated, high-impact head collisions may rely on a suite of coadaptations in intracranial physiology as a cost-reducing mechanism. We propose that there are three physiological systems that could mitigate the effects of repeated head trauma: (i) the innate neuroimmune response, (ii) the glymphatic system, and (iii) the choroid plexus. These systems are interconnected yet can evolve in an independent manner. We then briefly describe the function of these systems, their role in head trauma, and research that has examined how these systems may evolve to help reduce the cost of repeated, forceful head impacts. Ultimately, we note that little is known about cost-reducing intracranial mechanisms making it a novel field of comparative study that is ripe for exploration.


1998 ◽  
Vol 1998 ◽  
pp. 45-45
Author(s):  
R.M. Herd ◽  
J.A. Archer ◽  
P.F. Arthur ◽  
E.C. Richardson

Feed is the single largest cost in most animal production systems. Feed conversion ratio (FCR) is a commonly used measure of growth efficiency. Previous research has shown that FCR is moderately heritable and highly related to growth rate. While selection for FCR is beneficial to those feeding growing cattle for slaughter, any associated increase in the size of breeding females will mean this benefit will be at a cost to the calf breeder, as larger breeding cows require more feed.


2012 ◽  
Vol 60 (3/4) ◽  
pp. 248
Author(s):  
C. Quigley ◽  
R.P. Jones ◽  
R. McMurran ◽  
P. Faithfull

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