Every task can be broken down into three factors:
Specification: What someone wants done.
Time: How long it takes to do it.
Resources: What is needed to get it done.
Specification can be verbal or written, a casual request or a detailed description complete with deliverables and quality standards. Time may first involve a rough mental estimate or a detailed step-by-step flow chart or schedule. Resources include items like budget, staff, computer or equipment access, raw materials, or information.
If you’re like most people, when a task is specified, you make mental and sometimes written estimates of the time it will take you to do it, and the equipment, money, people, and information you’ll need to get it done. A task doesn’t exist in a vacuum. You have other tasks ongoing (some urgent), and you’ll have to adjust the time and resources you’ve allocated to those tasks and somehow fit in this one.