Look at several papers:

1) Malhotra and Trivedi in IEEE-TR, sept. 1995 compares SRN with GSPN

2) Also see chapter 8 section on automated generation in the second edition of my book on Prob & Stat.

3) For large models see many papers on decomposition (Ciardo and Trivedi in Perfomance evaluation 19193) and more recent ones using interacting stochastic models for VANET DSRC and for IaaS Cloud. Some of these papers can be downloaded either from my webpage or from Researchgate

I meant 1993 not 19193

I attach the relevant papers.

Here is the Malhotra paper

Here is the Ciardo 1993 paper