compare and contrast Systems Development Life Cycle

This research paper will compare and contrast Systems Development Life Cycle (SDLC Models).  The paper will be five pages:  (a) Describe the 7 Step SDLC - 2 pages, (b) Describe a different SDLC Model (4 step or 12 step) - 2 pages, (c) Compare and contrast the 7 Step Model and the second model you selected (4 step or 12 step) – 1 page.  DO NOT discuss Methods in this paper (waterfall, rad etc...).  You need to find other SDLC models, the models will be called SDLC ...some may have four steps and others may have 12 steps.   APA format; Minimum of 4 professional/peer review references.  Note: Professional references refer to books and journals.  (Typical internet resources are not considered professional resources).