Assembly costing model

through a straightforward analysis of a component s fitting characteristics. Therefore, the total cost of manual assembly, is  

In order to calculate an assembly cost, two further assumptions must be made  

1 The ideal assembly time for a combined handling and fitting operation is between 2 and 3 seconds. The exact time is dependent on factors such as workplace layout, environment and worker relaxation. In the case where an ideal time of 2 s is assumed, then the indices H and F can be taken as values in seconds. If 3 s is assumed, it is necessary to multiply the indices by 1.5 to obtain an estimate for the assembly time in seconds. 

2 The labor rate, Q, is calculated based on an annual salary of 15 000 (plus 40 per cent overheads for a worker in the UK), for a 250 working day year (5 day week minus statutory holidays), and a 7.5 h working day. This gives the cost of manual labor per second. Cl = 0.31 pence. 

31 Basic handling index (/Ah) for a selection of component handling characteristics. 

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The combination of the cost model and the optimization method will then give an augmented model from which the allocation of the component tolerances are optimized for competitive results. Optimization methods have also been extended to include procedures that select the most cost-effective manufacturing process for each component tolerance in the assembly stack (Chase and Parkinson, 1991). 

Research looking into tolerance allocation in assembly stacks is by no means new. A current theme is towards an optimization approach using complex routines and/ or cost models (Lin et al., 1997 Jeang, 1995). Advanced methods are also available, such as Monte Carlo Simulation and Method of Moment. ) (Chase and Parkinson, 1991 Wu et al., 1988). The approach presented here is based on empirical process capability measures using simple tolerance models, cost analogies and optimization... 

Before setting about the task of developing such a model, the product development process requires definition along with an indication of its key stages, this is so the appropriate tools and techniques can be applied (Booker et al., 1997). In the approach presented here in Figure 5.11, the product development phases are activities generally defined in the automotive industry (Clark and Fujimoto, 1991). QFD Phase 1 is used to understand and quantify the importance of customer needs and requirements, and to support the definition of product and process requirements. The FMEA process is used to explore any potential failure modes, their likely Occurrence, Severity and Detectability. DFA/DFM techniques are used to minimize part count, facilitate ease of assembly and project component manufacturing and assembly costs, and are primarily aimed at cost reduction. 

Bringing the process back under control requires a methodology that involves planning the printed circuit layout process with predictive wiring density models. The other benefits include reducing printed circuit fabrication and assembly costs. 

There are several cost factors to consider when establishing an assembly line the initial capital investment for the machine(s) depreciation and lifetime (obsolescence) of that equipment operational costs such as labor rates, electricity, water, or the use of inert atmospheres and maintenance support costs. Many of these cost factors are determined on a per product unit basis so that an estimate of potential production volumes is often required for their calculations. Many OEMs and CMS providers have had to estabUsh their own cost models to take into account labor rates, energy costs, shipping costs, and tax structures that are specific to the assembly plant location—on-shore as well as overseas. Because of the cost variables just mentioned, it is difficult to establish a universal model for these calculations. 

The JPL managers faced a situation similar to what supply chain partners now encounter. That is, how do you measure supply chain cost Table 25.12 describes some of the structural problems encountered and the consequences. To put everyone on a common basis, JPL developed a common cost model. Its purpose was to eliminate these differences when evaluating the underlying technology needed to produce solar cell systems. The model, called SAMIS for Standard Assembly Line Industry Simulation, used a structure that s adaptable for supply chain cost modeling. Figure 25.7 is a simplified structure of the SAMIS model. 

From this main objective on, it is established a secondary objective, to analyze the results from the application of the cited model to reduce production/assembling time, as well as the manufacturing/ assembling costs on the redesign of products from the reverse engineering. 

In addition to understanding the statistical tolerance stack models and the FMEA process in developing a process capable solution, the designer should also address the physical assembly aspects of the tolerance stack problem. Any additional failure costs determined using CA are independent of whether the tolerances assigned to the assembly stack are capable or not. As presented in Chapter 2, the Component... 

Cost targets exist for all parts of the fuel cell for bipolar plates, from 10/kW (2004) to 3/kW in 2015 for electrocatalysts, from 40/kW (2005) to 3/kW in 2015 and for membrane electrode assemblies (MEA), from 50/kW (2005) to 5/kW in 2015 (Freedom Car, 2005 these cost targets are somewhat different from those mentioned by the IEA (2005)). Since 2004, the number of fuel-cell cars has been growing and at the time of writing they numbered approximately 1000 worldwide there are also around 100 fuel-cell buses in use worldwide in several demonstration projects. But these cars are produced as individual (hand-built) models and are extremely expensive, with production costs per vehicle currently estimated at around one million large-scale production is not expected before 2015, see Section 13.1. 

In order to reduce costs and increase the flexibility of HCS readers, it is to be expected that academic laboratories will assemble automated microscopes themselves. Hopefully this will be done with the Open Source hardware (OSHW) model, allowing other laboratories to reproduce the design (http //www.open-hardware.org) (15, 16). 

The PetroTrap is available from the vendor at a cost of 885.00 per unit. The standard system includes a PetroTrap skimmer assembly (2- or 4-inch-diameter model), a 25-ft suspension hose, and a locking well cap (D17074L, p. 4). 

Mathematical modeling of the device function may also help to cut costs, since it allows more realistic specifications to be worked out with regard to functional requirements. In addition, mathematical modeling of the process sequence for microfabrication and assembly will be useful for cost saving. Such hard and... 

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