Traditional Planning Methods Research Articles

Component procurement under demand uncertainty for mainframe subassemblies

Journal of Electronics ManufacturingVol. 04, No. 01, pp. 11-15 (1994) PAPERSNo AccessComponent procurement under demand uncertainty for mainframe subassembliesR. SRINIVASAN, R. JAYARAMAN, B. DIETRICH and A. HAGUER. SRINIVASANManufacturing Research, IBM Research Division, Yorktown Heights, NY 10598, USA Search for more papers by this author , R. JAYARAMANManufacturing Research, IBM Research Division, Yorktown Heights, NY 10598, USA Search for more papers by this author , B. DIETRICHManufacturing Research, IBM Research Division, Yorktown Heights, NY 10598, USA Search for more papers by this author and A. HAGUEIBM Poughkeepsie (Retired), NY 12601, USA Search for more papers by this author https://doi.org/10.1142/S0960313194000031Cited by:0 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail AbstractThis paper reports on a study of a methodology to procure semiconductor components for subassemblies used in mainframe computers assembled in IBM. The demand for the subassemblies is highly uncertain as a result of the uncertain mainframe model demands. The demands for mainframe models are dependent on each other. There is also dependency among demands in several time periods. The component personalization process is several weeks long and hence orders for components have to be placed in advance. There is a lot of commonality of components in subassemblies and subassemblies in mainframe models. A software tool to perform procurement planning as well as some what-if analyses has been developed. Results are reported on the use of this tool to generate component requirements by considering set requirements for components, component commonality and dependency of product demands. The results, when compared with the traditional materials requirements planning (MRP) method, suggest that equal or higher service levels can be achieved for a given inventory budget; conversely, a specified service level can be achieved with equal or lower component procurement.Keywords:Commonalityinventoryservice constraintapproximationsprocurementstochastic demandsmaterials requirements planning FiguresReferencesRelatedDetails Recommended Vol. 04, No. 01 Metrics History Received 1 October 1993 Accepted 1 November 1993 KeywordsCommonalityinventoryservice constraintapproximationsprocurementstochastic demandsmaterials requirements planningPDF download

A theory of conflict resolution in planning

Conflict resolution in planning is the process of constraining a plan to remove harmful interactions that threaten its correctness. It has been a major contributing factor to the complexity of classical planning systems. Traditional planning methods have dealt with the problem of conflict resolution in a local and incremental manner, by considering and resolving conflicts individually. This paper presents a theory of conflict resolution that supports a global consideration of conflicts. The theory enables one to formally represent, reason about and resolve conflicts using an extended framework of constraint satisfaction. The computational advantage of the theory stems from its ability to remove inconsistencies early in a search process, to detect dead ends with low computational overhead, to remove redundancies in a search space, and to guide the search by providing an intelligent order in which to resolve conflicts. The paper also presents empirical results showing the utilities of the theory, by investigating the characteristics of problem domains where the theory is expected to work well, and the types of planning systems for which the theory can offer a marked computational advantage.

The land delivery mechanism in Tanzania: The implications for a socialist state

For many residents in developing cities, informal settlements are the sole avenue of access to shelter and basic services, however poor in quality. The need to improve the living conditions in such areas is once again receiving high priority on the international and national development agendas. Current approaches to settlement upgrading favour the adoption of community-based, participatory styles of planning and management. Upgrading inevitably also requires the use, albeit in cooperation with local residents, of more traditional planning and design methods which depend in part on the ability to analyse the physical setting of a given settlement and prepare appropriate solutions to specific problems. Using several examples from informal settlements in Dar es Salaam, it will be shown how a hybrid approach to spatial data provision that incorporates both the traditional sources of spatial data and some of the more participatory approaches can be beneficial. The hybrid approach built around the use of a series of low-cost, up to date aerial mosaics provides relevant spatial data that is relevant and usable by both residents and professionals, thereby presenting opportunities for more communicative and transparent discussions between actors on possible interventions in the settlement.

Factors Influencing the Use of Traditional versus Modern Family Planning Methods in Bas Zaire

Findings from a baseline survey conducted prior to the initiation of organized family planning efforts in one urban and one rural area of Bas Zaire reveal the widespread use of traditional methods and a surprisingly high level of knowledge of modern contraceptives. However, in the absence of a delivery system, use of the latter was extremely limited (4-5 percent of currently married women). The data reflect a deep-seated motivation for birth spacing, which is achieved primarily through withdrawal and abstinence. Of the variables tested as possible correlates, only economic status was related to use of both traditional and modern methods in the same direction. Use of a traditional method was largely determined by age of the youngest child and breastfeeding status. By contrast, use of a modern method was highest among women over 30 with higher levels of education and parity, who were not currently breastfeeding.

Using the CT-scanner to explore and circumnavigate current inadequacies in radiotherapy planning

Successful radiotherapy practice depends on the irradiation of tumours such that their destruction follows without unacceptable damage of the surrounding normal tissues. Until recently the accurate acquisition of data concerning the tumour anatomy lagged behind other developments in radiotherapy. Since the arrival of the CT scanner, these anatomical data can be displayed ideally for transmission into a computerised treatment planning system. The CT scan information concerning tumour location, irradiation volume and dosimetry was compared with results obtained using traditional planning methods. In this series, CT scanning appears to be useful in 65 of the 126 patients (52%).

A conceptual approach for the equilibration of supply and demand in commercial

This paper presents a conceptual approach for estimating demand and concomittant supply requirements for air passenger traffic within a network of interconnected cities. The area of consideration could be a state or collection of states. The suggested methodology represents a departure from the traditional sequential planning methods, by integrating simultaneously the elements of air demand and supply into an overall planning scheme. The scheme involves techniques ranging from mathematical programming to econometrics to represent the various components of the system. Typical results include such diverse items as passenger movements on each route by type of airplane, number of block hours by airplane type, capacity requirements at airports, and demand and supply sensitivities to air fares, energy factors, and services of other competitive modes.

Aggregate Planning with Learning Curve Productivity

Research reports of others indicate that many manufacturing organizations experience (a) the probiem of aggregate planning, and (b) experience systematic productivity changes throughout the “life” of a product. Methods for resolving (a) and for quantifying (b) have been developed and applied independently in the operations management literature. All current aggregate planning models are suitable only for constant productivity situations. The current research integrates (a) and (b) into a single computer-based model which permits the development of aggregate-output plans in the face of changing, productivity. The model requires reformulation of traditional aggregate planning methods to incorporate changes in productivity and thereafter solves the reformulated planning problem using direct-computer search. The potential significance of the model is demonstrated by generating a series of aggregate plans for various learning rates. These plans are then used to develop manpower schedules, for cash flow analysis, and for making product pricing decisions.

An Investment Planning Process for an Economy with Increasing Returns

In this paper, I propose a resource allocation (planning) process designed for an economy where increasing returns to scale prevail. The main feature of the process is to supplement the market mechanism by the central allocation of investment funds. It is well known that the unmodified market mechanism fails to solve optimal allocation problems, if non-decreasing returns to scale play a very important role in the economy. In order to meet the difficulty, Arrow and Hurwicz [1] introduced price speculation into a tatonnement process. Although locally convergent and informationally most efficient,2 their process is not entirely satisfactory especially from the motivational point of view. An alternative line of attack on optimization problems under non-decreasing returns may be found in rationalizing traditional planning methods of the central allocation of material quotas. This was first done by Kornai and Liptak [3] for the case of linear technologies. Later, in this Review, Heal [4] proposed a planning process based on essentially the same idea, but considerably generalized so as to cover non-convex technologies. In his process, each manager of a production process is instructed to report to the Central Planning Board (referred to as the CPB hereafter) the shadow prices of every input centrally allocated. In the light of this data, the CPB proposes a new allocation of inputs in which, by comparison with the previous one, resources have been shifted towards the uses where higher shadow prices are given. In this way, Heal has succeeded in defining a planning process with certain desirable properties, such as monotonicity and well-definedness3 in Malinvaud's sense [6], which the Arrow and Hurwicz process lacks. However, there are still some points to be improved on in this method:

A Simplified Approach To Transportation System Planning

The increase of passenger and goods transportation demand, both in urban or suburban and in intercity settings, has caused a notable growth of research activities in transportation science, technological, infrastructure, and organisational topics are involved in this field of research. This paper deals with transportation planning, with specific regard to public transport service supply, and it proposes a simplified approach to supply planning, suitable to case studies when no investment in infrastructure is envisaged. The interest in a simplified approach is motivated by the excessive burdensomeness of traditional planning methods, if compared with some particular problems. The proposed methodology is not intended to be opposite to the traditional one when a complete planning problem must be faced, but it can be useful when the cost of planning activities is expected low.