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Analys av kostnader vid tillverkning av mässingskomponenter med olika mängd blytillsatser

Rasmusson, Magnus LU and Sjöstrand, Stefan LU (2016) MMTM01 20152
Production and Materials Engineering
Abstract
This master thesis is a subproject of a research project run by Markaryds Metallamatur AB (MMA), the department industrial production at Lunds Technical University, Chalmers Technical University, The University at Halmstad and Oerlikon Balzers Sandvik Coating AB. The research project includes research about material properties, machining and a cost analysis of different brass compositions, primarily of different lead contents. The part that is going to be analyzed in this project is the cost analyze with the three different brass compositions; conventional brass (<4 weight % lead), brass with low lead content (<0.2 weight % lead) and lead free brass (<0.05 weight % lead).
In this project a dynamic cost simulation was done, between the... (More)
This master thesis is a subproject of a research project run by Markaryds Metallamatur AB (MMA), the department industrial production at Lunds Technical University, Chalmers Technical University, The University at Halmstad and Oerlikon Balzers Sandvik Coating AB. The research project includes research about material properties, machining and a cost analysis of different brass compositions, primarily of different lead contents. The part that is going to be analyzed in this project is the cost analyze with the three different brass compositions; conventional brass (<4 weight % lead), brass with low lead content (<0.2 weight % lead) and lead free brass (<0.05 weight % lead).
In this project a dynamic cost simulation was done, between the details with various lead compositions for the company MMA. This could later support in decision-making and contribute to an economic aspect to the larger research project. The analysis was performed on two different details that are both in the company’s new thermostat. One of the details is a coupling nut that is manufactured in low lead brass in the new invested machine and the other part is a socket, which is manufactured in conventional brass and Ecobrass in an older machine.
The manufacturing cost is calculated using a Monte Carlo simulation of a modified version of Jan-Eric Ståhl’s cost model. In the cost model, the manufacturing cost is divided up into the following different terms; tool cost, material cost, cost for the machine, labor cost for machining, surface treatment and washing. The necessary information was collected through interviews and documentation from the company.
The manufacturing cost for the connecting nut in low lead brass is 2.58 SEK and for the socket it is 1.62 SEK in conventional brass and 2.64 SEK for the one made of Ecobrass. It has shown that the purchasing price of the material have a great influence for all the details. The price of the material is between 59 to 63 percent of the total cost. 70 percent of the difference between the manufacturing costs for the socket depends on the purchase price of the material. Sensitivity analysis has shown that this is a solid analysis.
A general comparison for the MTW socket has been done over the hourly machine cost for various investment cost, expected lifetime and renovations. This shows that the lead free alternative is about 70-80 percent more expensive per part due to increased cycle time and increased downtime. However, one can see that an increase of the initial investment cost of 166 percent result in a change of approximately 10-11 percent of the retail cost in the end, at an expected lifetime of 10-20 years, while it presents a detailed cost increase of about 8 percent at an expected lifetime of 20-40 years, which is more like reality.
More work should be put at minimizing the purchase price of the material, through contracts with the suppliers, larger order quantities and a more intensive search of the cheapest supplier. Maybe it is possible for the company to develop a way to reuse the chips. From an environmental and health aspect it is purposed that the company puts their focus on the low lead brass material. The Ecobrass material is difficult to work with using today’s cutting tools and knowledge, furthermore the material cost is too high today. The marginal benefit of the difference between lead free brass and low lead brass is considered to be too small to justify the even more environmental friendly option. (Less)
Please use this url to cite or link to this publication:
author
Rasmusson, Magnus LU and Sjöstrand, Stefan LU
supervisor
organization
alternative title
Analysis of manufacturing costs for brass components with different lead contents
course
MMTM01 20152
year
type
H2 - Master's Degree (Two Years)
subject
report number
CODEN:LUTMDN/(TMMV-5271)/1-73/2016
funder
MISTRA
language
Swedish
id
8870709
date added to LUP
2016-04-05 13:22:37
date last changed
2016-06-16 13:02:44
@misc{8870709,
  abstract     = {This master thesis is a subproject of a research project run by Markaryds Metallamatur AB (MMA), the department industrial production at Lunds Technical University, Chalmers Technical University, The University at Halmstad and Oerlikon Balzers Sandvik Coating AB. The research project includes research about material properties, machining and a cost analysis of different brass compositions, primarily of different lead contents. The part that is going to be analyzed in this project is the cost analyze with the three different brass compositions; conventional brass (<4 weight % lead), brass with low lead content (<0.2 weight % lead) and lead free brass (<0.05 weight % lead).
In this project a dynamic cost simulation was done, between the details with various lead compositions for the company MMA. This could later support in decision-making and contribute to an economic aspect to the larger research project. The analysis was performed on two different details that are both in the company’s new thermostat. One of the details is a coupling nut that is manufactured in low lead brass in the new invested machine and the other part is a socket, which is manufactured in conventional brass and Ecobrass in an older machine.
The manufacturing cost is calculated using a Monte Carlo simulation of a modified version of Jan-Eric Ståhl’s cost model. In the cost model, the manufacturing cost is divided up into the following different terms; tool cost, material cost, cost for the machine, labor cost for machining, surface treatment and washing. The necessary information was collected through interviews and documentation from the company.
The manufacturing cost for the connecting nut in low lead brass is 2.58 SEK and for the socket it is 1.62 SEK in conventional brass and 2.64 SEK for the one made of Ecobrass. It has shown that the purchasing price of the material have a great influence for all the details. The price of the material is between 59 to 63 percent of the total cost. 70 percent of the difference between the manufacturing costs for the socket depends on the purchase price of the material. Sensitivity analysis has shown that this is a solid analysis.
A general comparison for the MTW socket has been done over the hourly machine cost for various investment cost, expected lifetime and renovations. This shows that the lead free alternative is about 70-80 percent more expensive per part due to increased cycle time and increased downtime. However, one can see that an increase of the initial investment cost of 166 percent result in a change of approximately 10-11 percent of the retail cost in the end, at an expected lifetime of 10-20 years, while it presents a detailed cost increase of about 8 percent at an expected lifetime of 20-40 years, which is more like reality.
More work should be put at minimizing the purchase price of the material, through contracts with the suppliers, larger order quantities and a more intensive search of the cheapest supplier. Maybe it is possible for the company to develop a way to reuse the chips. From an environmental and health aspect it is purposed that the company puts their focus on the low lead brass material. The Ecobrass material is difficult to work with using today’s cutting tools and knowledge, furthermore the material cost is too high today. The marginal benefit of the difference between lead free brass and low lead brass is considered to be too small to justify the even more environmental friendly option.},
  author       = {Rasmusson, Magnus and Sjöstrand, Stefan},
  language     = {swe},
  note         = {Student Paper},
  title        = {Analys av kostnader vid tillverkning av mässingskomponenter med olika mängd blytillsatser},
  year         = {2016},
}