## 3 Materials and Methods
### Decision Support System
#### 3.2.1 Development of the Decision Support System  
The user starts by accessing the DSS and is presented with a \"Home Page\", Figure 1, where they can get a brief idea of how the system works. Pressing the \"Start\" button opens a form, Figure 2, which asks the user what they want the program to do: calculate environmental impact or access their history. By selecting the \"History\" option, the user is directed to a page, shown in Figure 3, where the results obtained, as well as all the values entered in previous uses, are recorded.  
Figure 1: Home Page.  
Figure 2: Options form.  
If the user selects \"Calculate the Environmental Impact\", they will be directed to the \"Calculate Environmental Impact\" page, shown in Figure 4, where information regarding several parameters must be entered, whose value will be used to calculate the environmental impact associated with the process. The parameters to be entered must be measured in advance using whatever method the user finds most appropriate. The only restriction defined by the DSS is relative to the units. These concern the quantity of gaseous emissions, expressed in mg\(\cdot\)nm\({}^{-3}\); the quantity of effluents in mg\(\cdot\)dm\({}^{-3}\); and resource efficiency.  
As far as effluents are concerned, five factors are considered: chemical oxygen demand, which provides an estimate of water pollution--i.e., it measures the amount of oxygen needed to de-pollute water [21]; total Kjeldahl nitrogen, which measures the amount of nitrogen present in water [22]; pesticides; heavy metals; and absorbable halogenated organic compounds. The latter can be derived from the chemicals used in manufacturing processes. In turn, to calculate resource efficiency, the consumption of electrical energy in kwh, water consumption in m\({}^{3}\), and the amount of fabric manufactured in kg are considered.  
Once filled in, by pressing \"Calculate\", the DSS returns the value obtained, the level of impact the process is at, and an example of a label that can help the end consumer make environmentally conscious decisions using an environmental scale. The results page is shown in Figure 5.  
The environmental impact is, therefore, divided into five levels, represented by a set of dots and colors in ascending order (Figure 6). In other words, the first level represents the lowest level of impact, and the last represents the highest.  
On this results page, the user has three buttons: \"Save\", \"History\", and \"Finish\".  
By clicking on \"Save\", the program copies the results and values entered into the \"History\" sheet; in \"History\", it shows the database for previously saved calculations, allowing the user to follow the progress of their process; and in \"Finish\", the DSS clears the data entered and returns to the Home Page.  
Figure 4: Calculate the Environmental Impact page.  
Figure 3: History page.  
There are also two buttons in the \"History\" section, one that allows you to return to the results page and another like \"Finish\".  
All the buttons were created using Excel's Macros option as follows:  
* Insert the desired icon;
* In \"Programmer\", select \"Save Macro\";
* Name the Macro;
* Recreate the steps that you want the button to perform (for example, on the \"Start\" button, click on the \"Evaluate process impact\" sheet);
* Select \"Finish Recording\";
* Select the icon;
* Press \"Assign Macro\", and select the Macro you want.