im·ple·ment
1. to fulfill; perform; carry out;
2. to put into effect according to or by means of a definite plan or procedure;
3. to fill out or supplement.
In the days of cathedral building during the Middle Ages, the work of design and the work of building were overseen by the same man - the master builder. He spent the early part of the work designing while site preparation began, and then continued the dual roles of design and building even as the project took shape. The concept of the design could only be ultimately achieved by this accountability for the outcome.
Frank Lloyd Wright would oversee testing of his structural support designs - usually concrete - to make sure that the integrity of his design could be maintained by the capabilities of the materials he chose to work with.
In our age of technology and specialization it is difficult to understand this single-minded pursuit of implementation as a natural role of the designer. However, more and more projects are being initiated with accountability for outcomes placed squarely on the design lead, firm or team. Ultimately this introduces a certainty of outcome not possible in a highly specialized and fragmented organization of responsibilities.
Design-Build is becoming the preferred method for procuring facilities and managed services and cloud computing are becoming the preferred method of procuring IT services, where the underlying technology is only as good as the job it does in meeting customer requirements.