Method of preparing an installation of a false ceiling or wall comprising a plurality of ceiling or wall tiles, the tiles being mineral fibre based tiles, each having a front major surface being adapted to be visible, an opposing back major surface and one or more edge surfaces extending along the perimeter of the tile and connecting the front and back major surfaces (2, 3), the method comprising: calculating format, position and orientation for each individual tile in the suspended ceiling or wall, associating 202; 206) each individual tile with a unique tile identity, producing the individual tiles according to the calculated format, providing respective tile with the tile identity of respective tile, providing a representation of the false ceiling or wall including an association of the position of respective tile with respective tile identity, characterised in that the tiles are adapted to be connected to and suspended to a framework by a plurality of elongated suspension elements, the method further comprising calculating positions of connection points on the tiles or on connection elements interconnecting tiles at which connection points the suspension elements are adapted to be attached to the tiles or to the connection elements for suspension of the tiles, calculating, for each suspension element, an attachment position at which attachment position the suspension element is adapted to be attached to the framework, the calculation being performed relative to a representation of the framework, the calculation also including calculation of orientation and length of said suspension element, associating (202; 206) each individual suspension element with a unique suspension element identity, providing a representation of the suspended ceiling or wall including an association of the attachment position of respective suspension element with respective suspension element identity and including information concerning calculated orientation and length of respective suspension element with respective suspension element identity. calculating format, position and orientation for each individual tile in the suspended ceiling or wall, associating 202; 206) each individual tile with a unique tile identity, producing the individual tiles according to the calculated format, providing respective tile with the tile identity of respective tile, providing a representation of the false ceiling or wall including an association of the position of respective tile with respective tile identity, characterised in that the tiles are adapted to be connected to and suspended to a framework by a plurality of elongated suspension elements, the method further comprising calculating positions of connection points on the tiles or on connection elements interconnecting tiles at which connection points the suspension elements are adapted to be attached to the tiles or to the connection elements for suspension of the tiles, calculating, for each suspension element, an attachment position at which attachment position the suspension element is adapted to be attached to the framework, the calculation being performed relative to a representation of the framework, the calculation also including calculation of orientation and length of said suspension element, associating (202; 206) each individual suspension element with a unique suspension element identity, providing a representation of the suspended ceiling or wall including an association of the attachment position of respective suspension element with respective suspension element identity and including information concerning calculated orientation and length of respective suspension element with respective suspension element identity.