3. JUSTIFICACION
3.5. REDES DE ATENCIÓN DE EMERGENCIAS Y DESASTRES EN EL SECTOR DE
The cost estimation system is based on a generic cost estimation architecture. The prototype implementation is not based on specific manufacturing domain characteristics. Specific domain knowledge about costs is added to the system by means of the cost models defined with the system. Therefore, the system can be applied in different manufacturing domains.
The cost estimation architecture is based on the so-called Manufacturing Engineering Reference Model. This reference model has a central information management kernel that facilitates both the availability and the accessibility of meaningful representations of the evolving manufacturing information. As such, the cost estimation architecture fits in the system of co-operating architectures that can be arranged around the information management kernel. This means that the cost estimation function is integrated in the manufacturing process based on the information management kernel.
In the Cost Models module of the cost estimation system, the cost models are defined based on the cost structure. The cost structure incorporates cost types, cost functions and cost parameters. The flexibility of the cost structure and the relation to any object that causes costs allows the definition of different cost models. Because different cost models can be defined, it is possible to set them side-by-side and compare the results. Moreover, it is possible to define different cost models for different stages of the product development cycle, i.e. for different levels of aggregation. This means that the complete product development cycle can be supported with cost information. As a result, for any engineering task cost information can be made available for decision making.
The cost structures can be attached to the information structures, used in the Manufacturing Engineering Reference Model. As a result, the costs can be calculated for any object at any aggregation level in an information structure. Additionally, the costs can be stored in a differentiated way.
Through the use of the information management kernel, historic information can be accessed, which can be used for the deduction of cost functions or for variant based cost estimation. The Data Analysis module and the Data Tuning module of the cost estimation architecture can assure a proper use of the historic information.
The use of the centrally accessible information structures facilitates cost control. A cost view can show the position of costs in an information structure. The cause of these costs can be deduced based on the information structures and the cost structures. All the cost control functions determined by Liebers are present in the cost estimation architecture. So, it is possible to apply the four cost feedback loops: the engineering and planning feedback loop, the order acceptance feedback loop, the production feedback loop and the accounting feedback loop.
The major advantages of the proposed variant based cost estimation method are the flexibility in defining comparison criteria and in valuing the comparison criteria. Because of this flexibility, the method can be used in the whole product development cycle. Based on the use of the information structures, hybrid cost estimation can be dealt with more easily.
The application of the (partial) prototype cost estimation system has proven the suitability of the Cost Models module and the Cost Determination module. The definition of different cost models is possible. Although the Cost Determination module was not completely implemented, the use of the cost structures for the cost calculations has proven the generic nature of the cost calculation method. Based on this experience, the extension of the Cost Determination module will be relatively simple.
8.2 Recommendations
For the demonstration of the cost estimation architecture, a prototype system was implemented and tested by means of an example in the sheet metal domain. The implementation did not cover the complete architecture; only the most essential modules were implemented partially. In order to further test the cost estimation architecture, all the modules have to be implemented fully.
Currently, the Cost Determination module can only calculate the costs based on a selected cost model. The module has to be extended in order to allow cost calculations based on a pre-specified accuracy and based on the information available. This extension will enlarge the flexibility of the cost estimation system. Because the Cost Determination module is the cost calculation “engine”, this extension is very important.
Especially the Risk Analysis module has to be incorporated in the cost estimation system, because the accuracy of cost estimates is important information for a proper use of cost information. As described before, an existing analysis program can be used for this purpose.
Concerning the variant based cost estimation algorithm, it has to be noticed that the search and similarity calculation algorithms have to be optimised.
Furthermore, the prototype cost estimation system needs to be tested in practice. A test in combination with other systems based on the Manufacturing Engineering Reference Model would be ideal, though this is not necessary. The system can be enhanced by creating “standard” costs structures for various cost models and manufacturing domains. The “standard” cost structures can speed up the implementation of the cost estimation system in practice.
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Terminology
Acquisition costs Total expenditures estimated or incurred for the development, manufacture, construction and installation of an item of physical or intangible property, or the total acquisition costs of a group of such items.
Activity center Part of the product development cycle for which the costs are registered separately on request of management.
Activity pool Set of activities practised by a certain function.
Allocation base A measure that is directly related the amount of an activity used. Architecture An architecture is a framework which defines the functions, which are
required to perform the task of a system, with their input and output. Assembly An assembly is the result of physically combining components and/or
other assemblies, according to their mutual relations as specified in the product data structure.. An assembly is the result of physically combining components and/or other assemblies, according to their mutual relations as specified in the product information structure. Classification The process of grouping parts into families of similar parts; similarity
is based on some set of rules and principles.
Clustering The process of grouping similar objects based on a similarity coefficient.
Coding The arbitrary assignment of one or more symbols to a part, which when deciphered communicates specific meaning or intelligence. Company Management Company Management is concerned with the control of the customer
orders. It is responsible for the strategic decisions concerning the range of products which will be produced and the processes and resources which are required to this end.
Component A component is an atomic constituent of a product.
Concurrent Engineering The simultaneous execution of shared tasks by separate departments and the control of cooperative decision-making.
Conversion costs A grouping of direct labour and manufacturing overhead into a single summary cost element.
Cost actuator An object that causes costs.
Cost allocation A method or combination of methods that results in a reasonable distribution of costs.
Cost function A relationship between costs and manufacturing characteristics, i.e. cost parameters.
Cost model The collection of cost structures for which the method of cost calculation is the same and which covers the total manufacturing costs.
Cost modelling The determination of the data, ground rules, assumptions and equations that permits the translation of resources or characteristics into costs.
Cost structure A template to record the costs for all cost actuators.
Costs Costs is the amount of money of resources spend for the production of output.
Decomposition Decomposition of a system represented as a black box with a globally defined task, is the replacement of this representation with a configuration of system components, each with its own glabally defined subtask, that interact to realise the globally defined task of the black box.
Development costs Costs of a system up to the point where decision is made to procure an initial increment of the production units or the operational system. Direct costs Direct costs are costs that can be identified specifically and
consistently with an end objective (such as a product, service, program, function, or project).
Domain A domain is the representation of one aspect system in an information structure.
Engineering Engineering is that part of manufacturing that is concerned with the preparation of the actual production of a product. Therefore, engineering includes activities as design, process planning and production planning.
Fabrication Fabrication addresses those operations applied during production that are not assembly operations.
Face A face is the element of a component that separates that component from its surroundings.
Filter A filter can exclude information from a certain view.
Fixed costs Fixed costs are costs that do not vary with the volume of business. Form feature A form feature is a group of faces that together have an engineering
meaning.
Group Technology The technique of applying the same solution to similar problems. Indirect costs Indirect costs are costs that cannot be identified specifically and
consistently with an end objective (such as a product, service, program, function, or project).
Information Management Information management includes the functionality related to the initialisation, use, analysis and maintenance of information concerning orders, products and resources. Based on this, information
management can initiate processes in one of the engineering sections of the reference model.
Irrelevant costs Costs that do not play a role in a specific decision making process. Life-cycle costs All costs incurred during the projected life of the system, subsystem or
component (research, development, test, evaluation, production, maintenance and disposal).
Manufacturing Manufacturing refers to the series of interrelated activities and operations involving the design, the materials selection, the planning, the production and the quality assurance of the products. Manufacturing covers the complete product development cycle, of which production is only a part.
Module A module is a reference to a sub-assembly or a group of components, which -for reasons of convenience- is considered to be a distinct section of the geometric domain of the product data structure.