somashekar mentioned including design, which very often means packaging and delivery for ISO 14001. If alternative types of packaging would lessen the impact of disposal - for example, if reusable crates and pallets are practical - this can be captured in the design process.
Otherwise, typical lifecycle includes selection of raw materials for end product and processing. For example, if your cabinets need welding the corners the metal will need cleaning before welding. Your process design can include consideration of methods and types of chemicals to use for this cleaning. Is a noxious chemical needed when a water-soluble, biodegradable option would work?
When assessing the metal forming steps, consider the process steps that could reduce waste from cutting the components, trimming the sheet metal in pre-forming (configurations for bending to result in door and drawer frames, etc) which can include the waste in selecting the process to cut: will these shapes be notched with a die, or will the shapes be cut out with rotary cutting wheels? All the steps involve some type of material usage and perhaps waste. The type of usage and type of waste may be selected through process design. We can choose those with lower severity of impacts to the environment.
Impacts to the environment occur at every step. Planning processes can help reduce severity of impacts via selection of chemicals and other consumables. This can extend from receipt to delivery. Is there a way to reduce the number of truck loads to bring in raw materials and then send these finished cabinets to the customer? The carbon foot print of logistics is part of lifecycle too.
This seems disorganized, but can you see the lifecycle here?