Complexity and instructional design models

I have been thinking about the adoption or rejection of ID models and what that process entails. I have the following thoughts about it:

* Some ID models increase the number of design decisions to be made (Gibbons' layers, etc.)
* Some ID models seek to reduce the number of design decisions to be made (Gong's 3-person model, etc.)

* What are the reasons for increasing the number of design decisions to be made?

• Because: 
• I need more control over specific aspects of the design
• I need to improve the design but don't know where/what to improve

* What are the reasons for reducing the number of design decisions to be made?

• Because: 
• I need to reduce the complexity of what I am designing (too many design considerations to make progress)
• I need to expedite the design and development process (due to time, budget constraints)
• I need to isolate a part of the design process and improve it

These are just some thoughts that can guide my thinking about why I would consider other ID models over others. I think that selecting a design model is a matter of preference, expediency, and contextual constraints.