Well, technically a bar chart chart can show three dimensions and one expression. You get grouped stacked bars. And a block chart can also show three dimensions and an expression. And there's the trellis option too. But you should really first ask yourself what question(s) the chart should answer. If all you need is to see how many hours a certain employee worked on a certain machine on a certain day then a straight table or pivot table is probably the best solution. Don't underestimate the expressive qualities of a straightforward table (and sorting and highlighting can increase that some). If you need to compare between employees or compare between days or machines for a certain employee a bar chart may be a better choice. You may need more than one chart if there are really more than one question that should be answered.
