An effective tool for supply chain decision support during new product development process

The global marketplace has transformed supply chain design into a discipline which requires business sense supported by mathematical expertise. Several methods have been introduced to support supply chain design, most notably mixed integer programming. The current methods are tailor-made for situations where a product's bill-of-material is fixed. However, this assumption does not hold during product development where several competing product designs exist. Therefore this research investigates the question of what is an effective way to support supply chain decisions during new product development. The study is divided into four research questions, corresponding to the articles from which the dissertation is compiled: (1) Does a product structure-driven method exist for modeling and analyzing supply chains? (2) If such a method is discovered, what is its mathematical formulation? (3) Is there evidence to support the theoretical and practical usability of such a method? (4) How can strategic supply chain decisions be validated? Regarding question (1) the research finds that there is a shortage of methods that fulfill supply chain modeling and analysis requirements imposed by new product development process. During the research a Petri-net based method was constructed which satisfies these requirements. For question (2), the formal definitions of the constructed Petri net class are provided. Regarding question (3), the research finds that the created method and associated tool are useful aids when solving the question of the effect of demand variation and the number of product variants on the optimal supply chain. Furthermore, interviews with end users of the tool implementation provide evidence of the Petri net method's practical usefulness. Regarding question (4), the research finds that the validation of strategic supply chain decisions from companies' reporting systems is important, but it has not become a common practice due to the challenges in integrating various IT systems

DSSI protokollan saavutettavuusanalyysiin perustuva verifiointi

Tutkimus rinnakkaisten ja hajautettujen järjestelmien alalla on tuottanut useita formalismeja, joita voidaan käyttää suurien järjestelmien verifioinnissa. Tässä työssä esitetään DSS1 protokollan Petri verkkojen käyttöön perustuva mallitus ja analyysi. Työssä on kehitetty käytännön menetelmiä signalointikanavien, ajastimien, siirtovirheiden ja ylemmän protokollakerroksen primitiivien mallintamiseen Petri verkkojen avulla. Työssä on erityisesti keskitytty staattisten prioriteettien hyväksikäyttöön saavutettavuusgraafin generoinnin helpottamiseksi. Protokollan määrityksestä löytyi kolme virhettä, jotka esitetään korjauksineen työn lopussa

Utilization of waste sodium sulfate from battery chemical production in neutral electrolytic pickling

Abstract Several industrial activities produce metal sulfates, which are controlled by strict limitations for wastewater concentrations of sulfate. One emerging area where these activities occur is the production of lithium-ion battery chemicals in which sodium sulfates are formed because of cathode precursor co-precipitation. Several solutions for sulfate removal exist, but one option is to reuse the sulfate side stream in other processes to increase circular economy and atom efficiency. In this paper, the reuse of sodium sulfate solution in a steel industry pickling solution is considered. Neutral electrolytic pickling experiments were carried out to compare the pickling behavior of the electrolyte dissolved from pure sodium sulfate and the electrolyte diluted from a side stream solution. Effect of impure electrolyte was evaluated using field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectrometry (EDS). Concentrations of the metal ions were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). The results indicated a slight increase in current efficiency with the side stream electrolyte solution, while overall the pickling behavior remained similar. This suggests that a side stream sodium sulfate solution could be used as a pickling electrolyte, reducing the need for pure reagents