Please note! This essay has been submitted by a student.
The following is an EPE framework (Yingying Seow 2011). In this framework, the energy is consumed by various activities along with a manufacturing application. This is categorised into two groups: Direct and Indirect Energy. The EPE framework consists of the Indirect Energy and the Direct Energy. Direct Energy (DE) can be defined as the energy that is used by a number of processes within the facility that are needed to manufacture the desired product (e.g. welding, assembly processes, packaging processes, etc.).
On the other hand, Indirect Energy (IE) is basically the energy that is consumed by mundane activities that help to maintain the environment or the working space in which the production processes are carried out within a factory or manufacturing plant (e.g. lights, heating, and ventilation) (Shahin Rahimifard & Elliot Woolley 2013). Direct Energy (DE) can be expanded more by splitting it up into two sections. These two sections are Theoretical Energy (TE) and Auxiliary Energy (AE).
Theoretical Energy (TE) can be defined or seen as the minimum energy that is needed to implement the intended process or procedure (e.g. the energy required to mould or weld specific parts or specific materials together).
Auxiliary Energy (AE) can be seen or defined as the energy that is required by peripheral equipment or tools performing specific actions alongside the main process or procedure (e.g. a cooling mechanism within a machine that prevents machine from overheating). There is an existence of a systematic approach that can be used to calculate the DE and IE for different kinds of processes found within a production chain to make a product.
In order to define values of DE and IE, one can implement a combination of theory, empirical studies and/or reference sources (Shahin Rahimifard & Elliot Woolley 2013).TE can be calculated by considering values conducted from e.g. the specific cutting energy for a specific material (U), and also considering the volume of the material to be removed (V). This can be seen as (U x V) (Shahin Rahimifard & Elliot Woolley 2013).AE can be calculated by considering or looking into the systems specifications (e.g. data and information concerning equipment provided by manufacturers). If such data and information is not made available, empirical studies can be piloted and implemented to measure energy required for the auxiliary processes (Shahin Rahimifard & Elliot Woolley 2013).
To calculate IE, the energy that contributed in the proceedings of a product can be considered by compiling the total energy consumed within a zone or area (per hour), then we divide that by the number of products processed within that zone or area (per hour). The total of the TE and the AE or in other words the DE, together in addition with the IE for all of the processes within a production system make up the complete and the total Embodied Energy of the Product (EPE) (Shahin Rahimifard & Elliot Woolley 2013).A more in depth energy analysis and structure can be made and implemented by simply looking at the ratio of TE to AE (having a high value for TE and a low value for AE, illustrating an energy efficiency process).
Likewise, the ratio of DE to IE can be made (having a high value for DE and a low value for IE illustrating an energy efficient production system) (Shahin Rahimifard & Elliot Woolley 2013).There is an existence of three ratios and they are defined as follows:1. ER process (A): looks at the efficiency of the process during the manufacturing of product (A) = TE/DE.2. ER product (A): looks at the efficiency of the manufacturing of product (A) = TE/EPE.3. ER plant (A): looks at the efficiency of a production system during the manufacturing of product (A) = DE/EPE. ERprocess can be labelled under the inefficiencies that are encountered throughout non-productive Auxiliary Energy (AE) activities. ERplant can be labelled under the inefficiencies encountered throughout Indirect Energy (IE) activities. ERproduct basically covers both the inefficiencies that occur within AE and IE apparatuses.