There are about 200 Technical staffs in JSA. Throughout the long experience, many have excellent craftsmanship. Recording Recording the information ( position, size, quality, drawings, characteristics, etc.) of the dismantled and scattered stones. Dismantle, Trial Assembly, Assemble Dismantled materials are always under trial assembly before the real assembling. The position, size are checked. Repair work Previously broken materials are repaired and reused. Processing Newly quarried stones are processed similar to the original materials. Heavy Industrial Machine operation Heavy industrial machine are operated by teamwork. Quarry When new stones are needed, we cut out from the far away quarry developed by JSA. Excavate, Measure, Mapping Excavation is very important as a basic survey. Light wave measure machines and GPS are used for mapping. Organizing Relics Dozens of relics come out from the site. They are all cleaned and joint, documented by special staffs. Documenting Bas-Relief Precise survey of the bas-reliefs of Bayon has been held. The bas-reliefs are documented by hand writing.