1. A computer-implemented method for aggregating service components in a data processing system according to predefined aggregation rules, the method comprising: providing a plurality of visual elements, each visual element representing a corresponding service component; selecting a new visual element representing a new service component for addition to an aggregation structure, the aggregation structure including a set of sequences of instantiated visual elements of corresponding instantiated service components, each sequence defining an aggregated service within the aggregation structure, each instantiated visual element of each instantiated service component in each sequence comprising at least one condition selected from: preceding a following instantiated visual element of a following instantiated service component, and following a preceding instantiated visual element of a preceding instantiated service component; determining a set of eligible visual elements of eligible service components among the instantiated service components, the new service component being compatible for aggregation with each eligible service component according to the aggregation rules, the determining the set of eligible visual elements comprising: identifying one or more pairs of adjacent eligible service components, each pair of adjacent eligible service components belonging to a corresponding sequence in the set of sequences and including a preceding eligible service component and a following eligible service component that satisfy the following conditions: the intersection of Cp and Dn is non-empty, where Cp represents a co-domain of the preceding eligible service component and Dn represents a domain of the new service component, and the intersection of Df and Cn is non-empty, where Df represents a domain of the following eligible service component and Cn represents a co-domain of the new service component; associating, for each pair of adjacent eligible service components, a visual cue with the eligible visual elements corresponding to the adjacent eligible service components; and aggregating the new service component to the aggregation structure between the preceding eligible service component and the following eligible service component of a selected pair of adjacent eligible service components by inserting the new visual element between the visual element corresponding to the preceding eligible service component and the visual element corresponding to the following eligible service component.