An activity-based-parametric hybrid cost model to estimate the unit cost of a novel gas turbine component

Abstract

The first tool presented in this paper is a generic factory cost model that can estimate various costs at multiple levels of any manufacturing plant. The model is activity-based which means that the cost of each manufacturing operation is calculated and then summed up so that the true £-per-hour factory cost rate as well as the exact unit cost (i.e. manufacturing cost) of an unlimited number of different components can be estimated.The second tool is a scalable cost model that estimates the unit cost of future integrally bladed disc (blisk) designs which are used by the aerospace industry in gas turbine compressors. The tool multiplies the machine cost rates, calculated by the factory cost model, by the operation times derived from blisk scaling rules. As the operation times often depend on the number of blades, the disc diameter and other design variables, many scaling rules are based on the correlation between operation times and certain design parameters. Conversely, the remaining process times are constant because they are independent of the blisk geometry. As future process times can only be estimated and the correlation between operation times and design parameters is never perfect, all operation times have uncertainty distributions. These are cascaded through the model to generate a probability distribution of the unit cost.Through the interactive exchange of detailed cost information at the manufacturing operation level as well as extrapolated operation times, the two cost models facilitate design and manufacturing engineering to concurrently optimise blisk designs and manufacturing processes in terms of cost.

Design Automation for Customised and Large-Scale Additive Manufacturing: A Case Study on Custom Kayaks

“…Kayak STEP files for three different designs (that represented the designs with lowest, average and highest volume) were sent to a local AM provider used to perform AM process simulations in a AM software, ABB Robot Studio®. The data received from the AM simulations were then used to generate scaling rules (Langmaak et al, 2013), to provide input data for the cost model (Rickenbacher et al, 2013) and the carbon dioxide model (le Bourhis et al, 2014). One example of such scaling rules is the relationship between the print volume (from CAD file) and build time.…”

Development and application of a value driven design assessment framework to an unmanned air system design

“…The major disadvantage of this method is that it requires re-modelling, whenever any change in the manufacturing process takes place. Langmaak et al [35] presented a hybrid approach through the interaction between an activity-based cost model and a parametric scalable cost model, depending on the number of units produced, the geometry and other design variables, the operation times used for cost estimation are scaled.…”

“…They were also used in conjunction with bio-economic modelling to study production strategies and the use of soil nutrient resources [126], and with AHP and a fuzzy set based approach in the nuclear spent fuel management [127]. Value functions were combined with utility modelling, eliciting values (through linear value functions) 35 at lower-levels of the objectives hierarchy and assessing risk attitudes at higher levels [128].…”

Risk Modelling of Heavy Mobile Equipment to Determine Optimum Replacement Ages

“…It is generally accepted throughout the literature that activity based life-cycle costing (AB-LCC) is the superior method of conducting LCCs, as it is based on the physics, operations, operating environment, and business processes of the equipment. However, AB-LCC only become achieved prominence in the 21 st century because of the effort and intricacy of maintaining AB-LCC analyses ( [1], [3], [6], [7], [8], [9], [10], [11]). …”