Quality Requirements

This chapter defines the most important quality requirements for the system. Each requirement is specified as a concrete, measurable scenario.

Performance

The system must provide fast access to documentation content, even in large projects.

Table 1. Performance Scenarios

ID

Quality Goal

Scenario

Measurement

PERF-1

Response Time

When a user requests a typical section via get_section, the system shall return the content.

Response time < 2 seconds for a 10-page section within a 600-page project.

PERF-2

Indexing Time

When the server starts, it indexes the entire documentation project.

Initial indexing of a 600-page project completes in < 60 seconds.

PERF-3

Low Overhead

While the server is idle, it shall consume minimal system resources.

CPU usage < 5% and a stable, non-growing memory footprint.

Reliability and Data Integrity

The system must be robust and guarantee that no data is lost or corrupted.

Table 2. Reliability Scenarios

ID

Quality Goal

Scenario

Measurement

REL-1

Atomic Writes

When a user updates a section (update_section) and an error occurs mid-operation (e.g., disk full), the original file shall remain unmodified.

The file on disk is either the original version or the fully updated version, never a partially written or corrupted state. A backup/restore mechanism is used.

REL-2

Error Handling

When a user provides a malformed path to an API call (e.g., get_section("invalid.path")), the system shall return a descriptive error.

The API returns a structured error message (e.g., HTTP 400) with a clear explanation, without crashing the server.

REL-3

Data Integrity

After a series of 100 random but valid modification operations, the document structure remains valid and no content is lost.

A validation check (validate_structure()) run after the operations reports zero errors.

Usability

The system must be easy to use for its target audience of developers and architects.

Table 3. Usability Scenarios

ID

Quality Goal

Scenario

Measurement

USAB-1

MCP Compliance

A developer uses a standard MCP client to connect to the server and request the document structure.

The server responds with a valid structure as defined in the MCP specification, without requiring any custom client-side logic.

USAB-2

Intuitiveness

A developer can successfully perform the top 5 use cases (e.g., get section, update section, search) by only reading the API documentation.

90% success rate in user testing with the target audience.
Note
 USAB-3 (Web UI diff display) was removed per ADR-010 — dacli has no Web UI.

Scalability

The system must be able to handle large documentation projects.

Table 4. Scalability Scenarios

ID

Quality Goal

Scenario

Measurement

SCAL-1

Project Size

The server processes a large documentation project composed of multiple files.

The system successfully indexes and handles a 600-page AsciiDoc project with response times still within the defined performance limits (PERF-1).

SCAL-2

Concurrent Access

While one client is reading a large section, a second client initiates a request to modify a different section.

Both operations complete successfully without deadlocks or data corruption. The modification is correctly applied.