## 2 Literature Review  
### The Value Chain Modeling  
The VCOR model is organized upon seven attributes, linking the three domains of product development, supply-chain management and the customer chain across the supply networks. The structure of VCOR models supports and enables companies to integrate these three critical domains using one reference model to support the vision of an integrated value chain [4]. VCOR uses a \"process-based, common language\" of syntax and semantics while, at the same time, creates a base for the successful service-oriented architecture game plan.  
The main objective of VCOR is to increase the performance of the SC and support its evolution through four different layers:  
The Top Level (TL) of the model includes all the high-level processes. It is depicted through the process categories of plan-govern-execute seen as the \"Strategic Level\" (SL), where high-level decisions are made on gaining competitive advantages for the whole SC. The VCOR SL has three macro-processes:  
* Plan: this balances the current strategic objectives with the current asset status and produces decisions on activities to drive organizations toward the goals;
* Govern: this identifies and enables value-chain rules, policies, and procedures to control the implementation of plans and execute processes;
* Execute: this transforms customers' and product requirements into value-chain features. The executive processes operate within the limits of the management criteria.  
The second level of the model contains the processes decomposed from the SL to implement the goals set into a panel of tactics. This level, defined as \"Tactical Level\" (TL) can be described as an \"horizontal value-chain process re-engineering\".  
The third level of the model regards the gist of this study. This level focuses on the specific processes of the value chain and aids process improvements or process re-engineering, including new technologies deployment and KPI. Over a value chain perspective, this is the level where fine tunings occur.  
The VCOR model is based on high-level generic process categories suitable for all types of firms. Yet, the feature that perhaps is the reason for its success is the capability to define the level of performances for each process of the SC and to introduce best practices for the management of productive processes. Table 1 describes the processes considered within the model.  
Some interesting applications of VCOR and the value chain can be found in the seminal work of [3], in food wastes problems [5], in [6], and recently in the work of [7], in which the VCOR was implemented with green concepts.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Phase** & **Description** \\ \hline Market & Processes are finalized to understand market’s needs and translated into product service requirements \\ Research & Processes used in assessing, developing and transferring technologies \\ Develop & Creating the virtual definition and/or prototype of the product/service \\ Acquire & Procuring goods and services to forecasted or actual SC demand \\ Build & Transforming product to a finished state to meet the demand \\ Fulfill & Providing finished goods and services to meet planned or actual demand \\ Brand & Aligning brand strategy to business strategy and customer touch points \\ Sell & Activities associated in product/service selling \\ Support & Maintaining operational/economic performances of products/services \\ \hline \hline \end{tabular}
\end{table}
Table 1: VCOR Processes.