Grain boundary engineering(GBE) is a technique employed to tailor the grain boundaries and improve material properties. GBE involves deliberate manipulation of the grain boundary character distribution and the boundary network topology in the microstructure.The fundamental idea of GBE is to increase the fraction of certain coincident site lattice (CSL) special boundaries (Σ3-Σ29) and break the connectivity of random boundaries. Since annealing twin boundaries (Σ3) constitute the major proportion of the special boundaries in low to medium stacking fault energy (SFE) FCC metals and alloys,twinning becomes a crucial process in GBE. Strain annealing methodology in which the material is subjected to low strains ( 15%) followed by annealing is often employed to achieve a GBE microstructure. Introducing a small pre-strain enhances prolific twinning during annealing. Annealing twins are mostly observed to nucleate on migrating grain boundaries and triple junctions due to growth accidents. Commercial pure Nickel samples have been subjecting to 5%, 10% and 15% cold rolling reductions followed by annealing at 725C, 750C and 775C for different durations.The amount of pre-strain and annealing temperature are observed to influence the rate of formation, growth and annihilation of twin boundaries. Higher deformations and annealing time enhance twin formation in shorter duration.Prolonged exposure to temperature has resulted in annihilation of twins. A contrast in twinning behaviour is observed between 5% and 15% deformed samples.Through theoretical calculations on the variants of axis of CSL boundaries in triple junctions, the probabilities of outcomes of interactions of a few Σ3n (Σ3, Σ9, Σ27, etc.) boundaries are determined. This throws light on the significance of variant selection during twin nucleation and predict subsequent interactions of twins with other boundaries during grain growth. A phase field model for grain growth has been developed to simulate formation of different morphologies of annealing twins on grain boundaries and triple junctions during boundary migration. Through this model we evaluated the role of stored energy variations and their decay on twin formation and evolution. The evolution of microstructure and twin density during annealing in the presence of stored energy and its decay is analysed