Stovepipe System

Stovepipe system is also known as "legacy system", "Uncle Sam Special", and "Ad Hoc Integration". It is commonly seen at multi-system integrations.

Symptoms and Consequences

• Large semantic gap between architecture documentation and implemented software; documentation does not correspond to system implementation.
• Architects are unfamiliar with key aspects of integration solution.
• Project is over-budget and has slipped its schedule for no obvious reason.
• Requirements changes are costly to implement, and system maintenance generates surprising costs.
• System may comply with most paper requirements but does not meet user expectations.
• User must invent workarounds to cope with limitation of the system.
• Very hard to automate to the point where manual efforts are better.
• Interoperability with other system is not possible, and there is an inability to support integrated system management and intersystem security capabilities.
• Changes to the systems become increasingly difficult.
• System modifications become increasingly likely to introduce new serious bugs.

Causes

• Absent of a common mechanism makes the architecture difficult to describe or modify.
• Lack of abstractions; all interface are unique to each subsystem.
• Insufficient use of metadata; metadata is not available to support system extension and reconfiguration without software changes.
• Tight coupling between implementation classes requires excessive client code that is service specific.
• Lack of architectural vision.
• Lack of knowledge and having technical debt among architects and developers.

Refactor Recipes

• Establish a common interface across the enterprise.
• Realign all existing legacy system to the common interface.