Robert W. Grubbström

Bio: Robert W. Grubbström is an academic researcher from University of Ljubljana. The author has contributed to research in topics: Material requirements planning & Laplace transform. The author has an hindex of 33, co-authored 73 publications receiving 2382 citations. Previous affiliations of Robert W. Grubbström include Linköping University.

On The Application of the Laplace Transform to Certain Economic Problems

Abstract: During the last thirty years, the method of the Laplace transform has found an increasing number of applications in the fields of physics and technology. In this article the author points out the p...

A principle for determining the correct capital costs of work-in-progress and inventory

Abstract: In all production-inventory planning situations one of the major cost items to be considered is the capital cost for products in inventory and in the chain of process. In practical life as well as in theoretical models such costs are usually determined as a product value multiplied by an interest rate, where this value is computed on a cost-added basis: materials, labour, share of overheads, etc. In this paper we formulate models in which the physical production processes and their associated cash flow are analysed. By computing the present value of the cash flow as a function of characteristics of the production process, this value will also reflect a correct overall capital cost. Adjusting parameters of the physical process will then disclose what values to ascribe to products at different stages of production and assembly. It is shown that usual accounting principles often yield too conservative product values at early stages of production and that if percentage factors for covering overheads, etc., ar...

An Overview of Input-Output Analysis Applied to Production-Inventory Systems

Abstract: Input-Output Analysis, together with the Laplace transform, have been applied to multi-level, multi-period production-inventory systems in a number of papers. This article gives a historical overview of the areas involved in these studies. It is shown that the input and output matrices as well as the Leontief inverse can be generalised to include timing properties for the inputs by means of the Laplace transform. The consequent advantages are exemplified in different production models, treating, for instance, capacity requirements and safety stock problems. The main literature in this field concerns assembly systems, but the approach is easily applicable to process industries with a divergent material flow or when feedback is essential.

An exploration towards a production theory and its application to construction

Abstract: Vaitoskirja pyrkii vastaamaan kahteen kysymykseen: Onko mahdollista muotoilla tuotannon teoriaa? Jos on, johtaako teoria tehokkuuden kohoamiseen, kun sita sovelletaan rakentamiseen? Historiallinen analyysi paljastaa, etta 1900-luvulla on kehitetty ja sovellettu kolmea eri tuotannon kasitteellista mallia. Tuotanto on nahty muunnoksena, virtana ja arvontuottona. Kaikkia naita malleja voidaan perustellusti pitaa valttamattomina tuotannon ymmartamiseksi, ja niita tulisi siten soveltaa rinnakkain. Vaitostutkimuksessa esitettavaa tuotannon mallia kutsutaan tuotannon TFV-teoriaksi (Transformation, Flow, Value generation). Tutkimuksen tulokset osoittavat, etta tehokkuutta alentavia ongelmia esiintyy yleisesti rakentamisen kaikissa vaiheissa: rakennuttajan paatoksenteossa, suunnittelun ohjauksessa ja rakennustuotannon ohjauksessa. TFV-teoria selittaa suurelta osin rakentamisen ongelmien syntymisen. Tarkasteltaessa pioneeriyritysten kehittamishankkeita, joissa on sovellettu TFV-teorian tiettyja ydinpiirteita, voidaan havaita, etta talle teorialle perustuvat menetelmat tuottavat merkittavia kustannussaastoja ja muita hyotyja. TFV-teorian avulla voidaan siten suunnata uusiin tehokkaampiin menetelmiin tahtaavaa kokeilua ja kehitystyota seka rakentamisen kaytannon etta tutkimuksen piirissa.

Sociology of Science

Abstract: The Social Contexts of Research. Edited by Saad Z. Nagi and Ronald G. Corwin. Pp. xii + 409. (John Wiley: New York and London, August 1972.) £5.65.