Published papers

要旨：本論文では、複数の作業主体間で情報をやりとりしながら行われる間接事務作業を対象に取り上げ、改善の着想を導くために役立つ分析および改善のフレームワークを提示する。一般に、人手により行なわれている間接事務作業をそのまま情報システムに置き換えると、現状作業の問題点がそのままシステム化され、データベースが複雑になったりシステムが大規模・複雑化して、更新やメンテナンスに多大な工数とコストを要する。本論文では、対象とする間接事務作業を、各主体が行なう「作業ステップ」と、それらのステップで生み出された情報項目が主体間でやりとりされる「情報フロー」とで構成されるプロセスとして把握する。そして、対象とする間接事務作業の始めと終わりの時点に着目し、2つの時点の間をつなぐ変化のステップを、終わりの状態で必要な情報項目を始めの状態から生み出すために「必要不可欠な変化」、必要不可欠な変化のステップで用いられる情報項目を生み出す「補助的に必要な変化」、それ以外の「ムダな変化」、という3つに分けて捉えるフレームワークを提案する。それに基づいて、「フロー図」と名づけた図上に記述された主体間での情報のやりとりと各主体での作業を3つのレベルに分けて捉え、レベル間の対比から問題点と改善の着想を導く方法を提示する。このフレームワークは、ムダな変化に相当するステップを排除してシステム化の対象となる作業を改善したり、現状で用いられている情報項目をその重要度に応じて分類したり、必要不可欠な情報フロー・情報項目だけで構成される作業を設計する際に、ガイドラインとして役立つものである。 キーワード：間接事務作業、作業ステップ、情報フロー、情報項目、必要不可欠な変化、補助変化、作業改善、作業設計

Abstract. Economic evaluation of investment proposals is attracting a great deal of attention from many businesspeople including engineers and management executives as well as academicians who find themselves in today's uncertain economic environment. Methods typically employed to evaluate profitability and risk require sophisticated mathematical skills and therefore do not meet practical needs. The purpose of this paper is to propose graphic analytical methods for evaluating mutually exclusive investment alternatives from the perspective of trade-off between profitability and risk. The paper takes into consideration uncertainties in those factors, such as the amount of initial investment, annual return, annual expenses, interest rate, and product and machinery life. The paper proposes such visual charts as modified annual return domain, modified annual cost domain, break-even line chart, and slice cut chart, all of which facilitate quantitative trade-off analysis on uncertainties among the listed factors. Procedures for describing these charts are illustrated with a practical numerical example, followed by a discussion on how to utilize them in practice. Keywords: Engineering Economics, Uncertainties, Initial Investment, Annual Expected Return, Annual Expected Cost

Abstract. Many Japanese manufacturers are implementing various production revolution programs for their survival in the ever more severe business environment. Among those diverse programs, this paper investigates two that are attracting considerable attention in practice: ‘outsourcing’ of production function, and ‘cell production system’ introduced in many assembly lines. Both of these activities are expected to generate sizeable performance improvement results, the former by concentrating management resources on core business areas while cutting off non-core operations of the business, and the latter by making a leap in productivity at assembly lines. This paper first discusses concepts of ‘outsourcing’ and ‘cell production system’ in order to clarify often-forgotten key points to be noted in adopting them, while paying attention to the mechanism of how each of these concepts achieves business performance results. The paper presents viewpoints needed in evaluating these concepts from managerial viewpoints and considers each viewpoint citing practical cases. This paper then goes on to present three basic principles to be remembered in implementing truly fruitful productive innovation, giving views on managerial guidelines for implementing them. Keywords: Production Management, Continuous Improvement, Outsourcing, Cell Production System