1. RAD 型号：
RAD 模型是指快速应用程序开发，它是增量模型的类型。组件或功能是并行开发的，它可以处理小型项目和中型项目。在此模型中，可以在任何阶段进行任何更改。由于人数较少，因此生产率高。
2. 螺旋模型：
螺旋模型是一种软件开发生命周期模型，高度用于风险驱动模型。基于给定项目的风险模式，螺旋模型帮助开发人员提高模型的效率，因为大多数风险已经处理。它由许多形成螺旋形状的循环组成，其中每个循环称为软件开发周期的阶段。
RAD模型和螺旋模型的区别：
| S.No. | RAD MODEL | SPIRAL MODEL |
|---|---|---|
| 1. | Rad model is a software development model where by the components or functions are developed in parallel as if they were mini projects. | Spiral model is a software development model and is made with features of incremental, waterfall or evolutionary prototyping models. |
| 2. | Rad model requirements and early stage planning is not necessary. | Spiral model requirements and early stage planning is required. |
| 3. | RAD model is used between large and small project. | Spiral model is used for large project. |
| 4. | There is low amount risk in RAD model. | There is low amount risk in spiral model. |
| 5. | In RAD model small team size is required. | In spiral model large team is required. |
| 6. | Flexibility to change in rad model is Easy. | Flexibility to change in spiral model is not that difficult. |
| 7. | In rad model overlapping of phases is possible. | In spiral model overlapping of phases is not possible. |
| 8. | Testing is done in rad model after completion of coding. | Testing is done in spiral model at the end of the engineering phase. |
| 9. | Cost of rad model is Low. | Cost of spiral model is very expensive. |