Integrated Cost Reduction (Icr) of a Light Truck Frame – Design Approach 2007-01-4166
Cost reduction is an essential and continuous process to meet the competitive environment of product pricing and to increase the profitability of an organization. Integrated cost reduction exercise encompass all the possible avenue., e.g. Alternate material & it's procurement system, batch size, material handling, manufacturing process improvements, logistics and finally review & make changes to derive an optimum design and cost reductions to maximum extent.
This paper presents a systematic approach for achieving the cost reduction of an existing 5.7Tonnne LCV truck frame from design consideration. The methodology involves, identification of the components of the frame for the cost reduction, redesign of existing frame compatible to the cost reduction need, preliminary performance evaluation of the present frame and the cost reduction frame, redesign of the frame for the performance, detailed cost evaluation, prototype manufacturing, laboratory testing, vehicle level testing and final release for the mass production. Chassis designers contributed for major design changes to derive maximum cost reduction without compromising durability or performance deterioration due to bending or torsional stiffness changes from existing frame.
After a comprehensive study, it is identified that deletion of the boxing plate and the replacement of the tubular cross members with channel type cross members will contribute for the potential cost savings of the frame. With these inputs concept design of the cost reduction frame is arrived.
The important performance characteristics of a chassis frame are structural integrity (Strength and Stiffness) and durability. The existing and the cost reduction frames are evaluated based on these performance characteristics.
The final design of the cost reduction frame is arrived based on CAE analysis of the frame for structural integrity, Number of iterative operations got eliminated due to the use of multidisciplinary optimization (MDO) package. Different load cases which focus on strength and stiffness of the frame are considered as an example.
Bending and torsional stiffness of the existing and the cost reduction frames are also measured in the test rig. It is found that bending stiffness of the cost reduction frame is 9.15% more than the existing frame and torsional stiffness of the cost reduction frame is closer to the existing frame. It was also found that the durability of the existing and the cost reduction frame in bending is almost same. The test specifications are arrived based on strain measurements on the existing frame in our torture track.
The above methodology helped us in deriving a estimated cost saving of Rs.311/- by the modified frame design. There are other intangible benefits like savings in labour cost due to elimination of the boxing plate, savings in the processing cost of boxing plate welding etc. The estimated cost savings is likely to be double of the above amount and would result in 3.5% of the Chassis frame aggregate cost.