  This paper pushes further the intrinsic capabilities of the GFEM$^{gl}$
global-local approach introduced initially in [1]. We develop a distributed
computing approach using MPI (Message Passing Interface) both for the global
and local problems. Regarding local problems, a specific scheduling strategy is
introduced. Then, to measure correctly the convergence of the iterative
process, we introduce a reference solution that revisits the product of
classical and enriched functions. As a consequence, we are able to propose a
purely matrix-based implementation of the global-local problem. The distributed
approach is then compared to other parallel solvers either direct or iterative
with domain decomposition. The comparison addresses the scalability as well as
the elapsed time. Numerical examples deal with linear elastic problems: a
polynomial exact solution problem, a complex micro-structure, and, finally, a
pull-out test (with different crack extent).
  1: C. A. Duarte, D.-J. Kim, and I. Babu\v{s}ka. A global-local approach for
the construction of enrichment functions for the generalized fem and its
application to three-dimensional cracks. In Advances in Meshfree Techniques,
Dordrecht, 2007. Springer
