First, a project is a project whether it’s small or large. It’s has a start and an end date. It’s going to yield a unique deliverable, and your delivery is a solution to a problem. The complexity between small and large varies, and sometimes we are of the mindset that small is simple and large is complex, but that’s not really true based on my experience. Sometimes small projects are more complex; it depends upon what you’re doing. You could be implementing something that’s never been implemented before: maybe a new type of landscaping, a new technique for building a pond, or using new building materials. Maybe the solution is for a different country where the basis of the project is different than you’ve never dealt with before. On the other hand, a large project could be large but simple. It could have a really huge budget with a lot of resources, but if it is repeatable, something that you’ve done many times before so you have a sound, mature process, tools and templates already in place and people who are really good about executing then it may not be so complex.
Large scale complex projects require attention from various areas.
Business analysis(identifying the functional requirements of the clients business). Identifying the technical requirements for handling and fulfilling of those business requirements. Identifying the project personnel based on the budjets. Building of team etc.