# Grasshopper Algorithmic Modelling: Parametric Design for Product Platform Customisation
## 3 Methodology  
This study adopts a multiple case study method with an exploratory, comparative approach [68] to evaluate the feasibility and effectiveness of algorithmic modelling using GH in the design of product platforms. Three representative cases from different areas of industrial design were selected to cover a variety of functional and use-related contexts. The methodology was structured into the three phases shown in Figure 2: (1) definition and modelling of each platform using GH; (2) identification and classification of design parameters, distinguishing those related to the product and the platform; and (3) multi-criteria analysis to quantify the influence of each parameter on platform customisation. In the first phase, three product platforms were selected, each representative of different areas of industrial design (packaging, furniture, and office organisation), with the aim of covering a range of functional, aesthetic, and contextual requirements. The selected cases encompass all platform typologies described in the literature and commonly used in industry [10,11]: (1) scale-based platforms, which allow resizing or adapting a base design to offer products with different capabilities or performance levels, and (2) module-based platforms, which rely on the combination and interchangeability of standardised modules with a shared architecture and defined interfaces. Parametric models were developed by constructing algorithms in Grasshopper 1.0 and Rhinoceros 8.0, allowing for flexible configuration of each platform through automatic modification of design parameters (dimensions, proportions, colour, shape, rounding, materials, and pattern). This process enables the customisation of the derived products, adapting them to specific user needs and use contexts. The second phase identified the analysis variables required to assess the feasibility and effectiveness of GH algorithmic modelling in the design of the product platforms. These variables were structured into two groups: Group 1 with product design parameters and Group 2 with platform design parameters. In this context, design parameters are understood as configurable attributes in GH that define the functionality, appearance, or user adaptation of a product (Group 1) or a platform (Group 2). Table 1 presents both sets of parameters and defines their scope in terms of customisation of product design customisation. Group 1 (PR\({}_{i}\)) includes the attributes and properties of the product that allow evaluation of its level of customisation (or user adaptation): dimensions, proportions, colour, shape, rounding, materials, and pattern. These parameters can be configured directly within the parametric model. The selection was based on its ability to control the visual and aesthetic aspects of the product; in addition, only those parameters whose manipulation is technically feasible in GH without the use of external resources were included. Group 2 (PL\({}_{i}\)) includes parameters to evaluate the product platform from a market perspective: scalability, modularity, usability, ergonomics and context of use. An appropriate combination of these properties allows manufacturers to develop a diversified product offering tailored to user groups with highly differentiated needs. The selection was based on their relevance as essential requirements that a platform must meet to effectively adapt to a specific market segment and ensure its economic viability. In phase 3, the level of customisation offered by each parametric model developed in GH was evaluated. A systematic observation process was carried out to document the behaviour of the model when modifying the parameters listed in Table 1. The results were used to analyse the feasibility and effectiveness of algorithmic modelling with GH in the design of product platforms. Figure 2: Research methodology. The evaluation process was based on a multi-criteria analysis to quantify the relationship between the parameters of group 1 (PRI, product design) and group 2 (PLI, platform design).