The trowel, level, and mixer are essential tools for masonry. Increasingly, so are the personal computer and the growing selection of software to aid in masonry design. Now in most architectural and engineering offices, computers make it easier to design with and specify masonry. Dynamic modelling, finite element analysis, and other techniques not practical without computers enable engineers to study specific design loads and conditions and use masonry in ways not previously possible. Computer-aided design (CAD) allows designers to experiment with decorative brick patterns and other special treatments. Where masonry construction methods were once relatively standardized, today's variety of masonry systems has increased the importance of clear construction documents. Reinforced masonry, insulated walls, veneer systems, and high-performance fire-rated or acoustically rated systems each require careful attention to detailing and specifying. Software can lead designers step-by-step through the detailing process. The directory of software provided indicates the variety of software designers have from which to choose.