Question: How do you overcome the expectation for a complete product when you are delivering piece by piece?
The idea behind incremental delivery is that each individual piece delivered to the customer provides some value, although not all of the value that the overall product is expected to provide. If the product is a system for internal use by some part an organization, say a claims processing system, claims processing system, or conference submission system, the first pieces may support parts of the overall process and handle only the most common cases. Future pieces that are delivered may handle more portions of the process, or may extend the handling of parts of the process already cared for in more unique cases.
The value in this approach is that worthwhile parts of the product are available for use much sooner than if nothing was delivered until the entire product is ready. Earlier access to some functionality provides the opportunity for the stakeholders to provide meaningful feedback based on meaningful use of the product as it was intended to be used and it generates some value to the organization by generating some efficiencies that may help make the case for further development of the product. Incremental delivery may also allow the product owner to discover that a subset of product features are sufficient to meet their needs and can stop development on less valuable features, resulting in less complex, less costly products.
To make this work, each piece that is delivered needs to have sufficient functionality to be useful, especially the first piece released. Delivering a login screen by itself is not going to be too useful to the sponsoring organization. This concept can be described as a Minimal Marketable Feature as described in Software By the Numbers.
