Their problem was that both the membrane current l M and the membrane potential V M are also changing constantly during the action potential. Now if one of these variables could be held constant during the action potential (i.e., V M), measurement of l M would enable them to calculate g M at any instant.
The CMMi Easy button notes on Product Integration (PI) Process Area Product Integration (PI) is one of the core Engineering Process Areas within CMMi, this process is concerned with assembly of product components to build the finished software product.
System integration (SI) is the process of implementing new systems that interface with existing systems. It applies to every human discipline, either simple or complicated. SI requires a lot of planning, implementation, and optimization.