This shows the lifespan of the light source. Projectors need to have their lamps (light source) replaced every now and then.
We consider a lower weight better because lighter devices are more comfortable to carry. A lower weight is also an advantage for home appliances, as it makes transportation easier, and for many other types of products.
The width represents the horizontal dimension of the product. We consider a smaller width better because it assures easy maneuverability.
We consider a thinner chassis better because it makes the product more compact and portable. Thinness is a feature highlighted by many manufacturers of mobile devices, but it is essential for a wide range of products.
The height represents the vertical dimension of the product. We consider a smaller height better because it assures easy maneuverability.
Volume is the quantity of three-dimensional space enclosed by the product's chassis or, in simpler terms, the space the product occupies.