Analog Designers created Spice, Analog Design Professionals are adding their experience in many commercial and free spice EDA tools. When you are creating a new demanding design, a working solution is achieved by combining workbench and simulation work.
Lab Test Bench and Breadboard testing needs to be done along with analog simulation. Power and mixed signal design too, needs to be verified on board. This is more true for a new design lab or new engineers. Experienced designers will not make many mistakes as design blocks would be in their collections or in their knowledge base. It is this knowledge that can build the simulator itself, this makes the simulator as skilled as the designer but also limited to his or that firm’s experience. In a full digital design, simulation does a more complete Virtual Test bench role.
A simulation tool can help you test the blocks and helps catch some design and concept errors. When you build a live breadboard prototype, some real issues facing your design can emerge.
SPICE (Simulation Program with Integrated Circuit Emphasis) is a general purpose analog electronic circuit simulator. It is a powerful program that is used in IC and board-level design to check the integrity of circuit designs and to predict circuit behavior. – Wikipedia