Diff btw waterfall model and spiral model

Waterfall model spiral model

In this, the customer is not involved In this, the customer is involved in the s/w dvlpmnt

from the word go.

When the development process shifts to the next

stage, there is no going back.

Since there are different iterations, it is rather

easier to change the design and make the s/w

feasible.

Waterfall allows no such scope. Here, one can revisit the diff phases of s/w dvlpmnt

as mny tyms as poss.

Has sequential progression, with clear

documentation of the entire process.

Has complex model.

Least flexible model. The most flexible model.

It is document driven. Does not require document.In Waterfall model each step is distinct. In spiral model we dont define everything in detail

at very beginning.

The output is not known unless all stages are over. The final output is known from the beginning.

s/w developer knows the actual problem. s/w developer does not know the problem.

Has five main phases namely; requirement, design,

implementation, verification and maintenance.

Has four main stages which are objectives, identity,

dvlpmnt and planning.