The BILLY bookcase, measuring 80 × 28 × 202 cm, is assembled using IKEA's official instruction manual (AA-1823127-9) as the structural foundation, with an interactive 3D visualization following each step precisely. The manual details 82 hardware components: 16 wooden dowels, 12 cam screws, 12 cam locks, 18 nails, 16 shelf pins, and 2 wall brackets with accompanying screws and washers. Assembly relies on cam locks for structural integrity, where cam screws inserted into side panels engage with round cups (cams) in adjoining boards; a half-turn clockwise pulls panels tight, while dowels merely align components. The back panel, secured with nails, prevents racking. Users navigate the 3D model via arrow keys, spacebar, or timeline controls to view steps, jump to specific pages, or hear part names read aloud. A separate interactive guide for the LACK side table (55 × 55 × 45 cm, manual AA-2606170-1) simplifies assembly to four double-ended screws and legs, requiring only manual placement of legs before flipping the unit. IKEA emphasizes wall anchoring to prevent tip-overs, issuing warnings about stability and directing users to select wall-specific screws and plugs not included in the package. The 3D tool operates faster than manual assembly and recommends two people for lifting or turning heavy components. All part dimensions, counts, and hardware specifications are derived directly from the original manual, with panel thicknesses and hole positions approximated from drawings rather than measured. The interactive feature, accessible through keyboard commands and mouse controls, allows users to explore the assembly process in a black-line style mirroring the printed manual, though the original manual remains the authoritative reference. IKEA trademarks BILLY and LACK, and the 3D guide is reproduced unaltered from their 2024 publication, with no endorsement from Inter IKEA Systems B.V. beyond the source material.