This paper discusses a version of the vehicle routing problem with stochastic demand (VRPSD). In this problem, a customer's demand is characterized by a known probability distribution and the customer's actual demand is only revealed when the vehicle reaches the customer location. In such a problem, two approaches are proposed. The objective of the first approach is to find a route sequence that minimizes the expected travel cost. This approach has good performance stochastically; however, when it is applied an upper bound on the travel cost cannot be guaranteed. The second approach is a robust approach implemented through chance-constrained programming. The objective is to find a route sequence that is robust with respect to uncertain demands and, at the same time, minimize the travel cost. When the probability that the vehicle's route is executed as planned is high, the route is said to be robust. In chance-constrained programming, the maximum allowable probability of route failure can be specified by the planner. The chance-constrained approach may have a higher travel cost than the first approach; however, it can guarantee a boundary for worst case performance. In this paper, we employ the chance-constrained approach as a robust method. We formulate VRPSD as a set-covering problem and solve the problem using column generation. We propose an efficient method for designing the route sequences that enable the maximum allowable probability of route failure to be specified.

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An event-driven network approach using queueing theory to reduce the waiting times of outpatients for hospital is presented in this paper. First, an object including all queueing for medical examinations and treatment departments at the hospital is built using an event-driven network model. Next, a queueing model in which the arrival distribution and service distribution are conformed as a M/G/s queue for the general reception. For the second factor, the walking speed of outpatients is given; the travel time of outpatients is decided in direct relation to two medical examinations and the distance between the respective treatment departments. The dispatching rules assigned to each outpatient are suggested based on their expected visitation time and the expected service time necessary for each outpatient. Next, situations are assessed relative to the windows of medical examinations and treatment departments, and when outpatients have single check-ups or plural check-ups. When they are plural, the windows of medical examinations and treatment departments are either crowded or vacant. Then outpatients are scheduled using suggested dispatching rules. Subsequently, the effects of the proposed approach for dispatching rules of the total waiting time for each outpatient are verified using numerical experiments.

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The international situation is changing rapidly and information technologies are evolving faster in recent years. As a result, requirements for production have become widely diverged and highly sophisticated. Production flexibility is also required to enable the development of single manufacturing machines, manufacturing lines and factories utilizing supply chain management. This is one of the key enablers for meeting the challenges of global competition. In this paper, researches on the concepts of flexibility are first reviewed. Then, several examples of flexible assembly systems are demonstrated. The production systems introduced are those that the first author was involved in during their development for practical use in the 1980s and 1990s. They are all production systems that correspond to quantitative fluctuation in the extension of mixed production systems. The production systems are evaluated and compared with conventional systems using a performance function, "Life-cycle Cost Analysis" and a simulation technique under the assumption of several fluctuation patterns for production volume. In addition, in order to appropriately identify the different flexible production systems, a definition of "Reconfigurability" is proposed. The results show that the flexible production systems and simulation technique contribute to more efficient production management. Additionally, "Reconfigurability" describes the characteristics of the flexible production systems.

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This paper discusses the effect of localized vibration on tactile sensing at the fingertip. Cusp surface analysis was utilized where each subject's emotional instability, discrimination ability and localized vibration at the fingertip were the factors of analysis. A subject's discrimination ability properly was quantified using the magnitude estimation method. The results of cusp surface analysis, it is clarified that a catastrophe phenomenon generates in the relationship among emotional instability, acceleration amplitude and discrimination ability. In the range of the bifurcation set, it was shown that when the acceleration amplitude of localized vibration is increased, the probability of lower level mode in discrimination ability increases, and when emotional instability increases, the probability of lower level mode in discrimination ability increases.

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The invisible hand in economics is generally well-known, and is hypothesized to attain a win-win situation in the division of work. Here, this invisible hand of God would be regarded as "demand speed" in Matsui(2008), and the system balancing problem using demand speed is considered stochasti-cally using a station-centered approach. This paper discusses a stochastic approach to a system, or risk balancing/re-balancing using the cycle time (demand speed) and shifting from an assembly line approach toward a demand (supply) chain, and presents a fundamental theory for the cost/profit balancing of excessive penalties derived from demand speed. First, the two cost approaches are prepared based on balancing issues. Next, line balancing using expected cost is summarized, and chain balancing using stochastic cost is discussed. Finally, these two in-teresting problems for balancing are discussed in terms of future developments in the world of the invisi-ble hand (demand speed).

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In the recent trend of increased variety and shorter life of products in the market, the evaluation of risk for economic investment alternatives is of practical importance in manufacturing companies. In the area of engineering economics, the problem is formulated based on such assumptions as a single item, stable demand, sufficient production capacity, and/or perfect quality and yield. This paper investigates the problem based on the assumption that demand fluctuates from period to period, resulting in either a surplus or shortage of production capacity in each period. The paper also takes yield into account. The fluctuation of yield makes the problem more complicated, requiring the judgment as to whether or not capacity is in surplus or in shortage when investment risk is being evaluated. This paper assumes that the values of sales price, demand quantity, unit variable cost, and annual fixed cost fluctuate from period to period throughout the planning horizon. It proposes a domain comprising total cost and unit cost axes as a tool for analysis. A method for quantitatively evaluating investment risk alternatives is developed by applying the concept of breakeven points for the factors under consideration. The validity of the proposed method is verified using a numerical example.

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To predict a project's quality, cost, and delivery (QCD) in the early stages of software development, we have been implementing risk management, earned value management (EVM), and quality assurance activities. This paper discusses a multiple linear regression analysis using these process measurement data and derives a relational expression which predicts the quality of software products quantitatively. From this analysis, we examine the effects on a software product's quality for these management and quality assurance factors. Based on our results, we have a clear correlation among these activities and software product quality. The prediction of product quality using process measurement data is shown to be a very effective way to clarify the process factors that affect product quality and to promote the improvement of process factors. Based on the process data for effective management factors, we also derive a discriminant expression to judge whether or not the software project has a quality process.

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