As part of the GOCE User Toolbox Specification(GUTS) project, the GUTS team has carried out ascientific trade-off study, to select the best algorithms tofulfil the user requirements for the toolbox. In somecases the selection is straightforward. However, in othercases, the choice depends on scientific applications aswell as the algorithm efficiency and more practicalconsiderations. Studies need to be performed todemonstrate the best possible algorithm. One example isthe selection of filtering functions and the choice ofinterpolation schemes used in calculation of a meandynamic topography from combined GOCE and satellitealtimeter data. The trade-off study has also selected thefunctionality of the toolbox, given the user requirementsand the recommended algorithms. In this paper wepresent the proposed functionality of the toolbox, andthe most important algorithm selections. As part of thescientific trade-off, a pilot application is investigatingvalidation of mean dynamic topography, generated frompseudo observations using proposed toolbox algorithms,against ocean model data. The study includes resultsfrom research into methods of calculation of meandynamic topography and filtering methods presented atthis workshop. workflow of the toolbox that will provide solutions forthe geodetic, solid earth and oceanographiccommunities. The scientific trade-off study has focusedon the different filtering methods necessary to mergegeodetic and satellite altimetric data to produce dynamictopography fields. The effect of different filters on theaccuracy of the solution is studied along with thecomputational cost and the cost of implementation ofthe filters. Other factors in evaluating different filtersinclude their general applicability and their priority,based on known qualities of the individual filter.