  Several complexity metrics are described which are related to logic
structure, data structure and size of spreadsheet models. They primarily
concentrate on the dispersion of cell references and cell paths. Most metrics
are newly defined, while some are adapted from traditional software
engineering. Their purpose is the identification of cells which are liable to
errors. In addition, they can be used to estimate the values of dependent
process metrics, such as the development duration and effort, and especially to
adjust the cell error rate in accordance with the contents of each individual
cell, in order to accurately asses the reliability of a model. Finally, two
conceptual constructs - the reference branching condition cell and the
condition block - are discussed, aiming at improving the reliability,
modifiability, auditability and comprehensibility of logical tests.
