Context and System Boundary Facts: The proposed product is an online, responsive community room booking portal replacing scattered email requests and spreadsheet copying. The pilot business goal is to record each request and show its current status. The fictional pilot includes five coordinators, 30 adult members, 50 requests per week, and up to five simultaneous users. Main use cases are request creation, coordinator approval or rejection, requester status viewing, and email confirmation. Existing systems are a shared spreadsheet and organization email. E1–E3 are illustrative fictional notes, not real research findings or evidence of demand. Inside the system: Requests, ownership, statuses, access enforcement, and notification tracking. Three screens: request form, member request list, and coordinator queue. Authentication integration and application authorization. Outside the system: Email delivery infrastructure. Finance, payment collection, public profiles, mobile applications, and analytics dashboards. Physical room management and any unprovided scheduling rules. Decision: Investigate status visibility first. E2 directly illustrates uncertainty about approval, and E3 illustrates manual status communication. This is a discovery priority to verify, not a validated finding. Treat the portal as a request and decision system. Approval does not yet guarantee conflict-free room allocation. Open questions: Required request fields and room scheduling rules. Whether approval must prevent overlapping bookings. Authentication mechanism and account administration. Quality and Constraints Functional must-haves: Authenticated members create requests and view only their own requests. Coordinators view all requests and approve or reject them. New requests appear as pending. Decisions remain visible independently of email delivery. The system sends email confirmation; the precise notification events require agreement. Non-functional requirements: Security: enforce role and ownership checks on the server for every protected operation. Privacy: collect only name, email, and necessary request details; exclude health data. Retention: delete request personal data after 90 days. The retention starting point and treatment of accounts, logs, and backups remain open. Performance: verify representative workflows at the supplied pilot load. Response-time targets remain unknown. Availability and recovery: service hours, recovery time, and acceptable data loss remain unknown. Maintainability: separate request rules, authorization, persistence, and notification responsibilities. Observability: record failures and decision changes without copying request contents into logs. Cost: engineering effort, implementation cost, and operating budget are unknown. Portability: retain exportable application data and document provider dependencies. Constraints: Online only. No payments or public personal profiles. Use an existing managed relational database and web framework; specific choices remain open. No production changes in this exercise. Potential conflict: A room “booking” portal could imply availability guarantees. The supplied scope specifies request approval but provides no collision rules. Such guarantees cannot be assumed. Architecture Overview Decision: use one application with clearly separated modules and a managed relational database. The supplied load does not justify independently deployed services. Module Responsibility Inputs Outputs Stored data Dependencies Scaling unit Failure impact Web interface Present three screens User actions; application responses Validated submissions; status displays No authoritative browser copy Application endpoints Application instance Users cannot submit or view requests Identity and authorization Establish identity; enforce roles and ownership Authentication result; requested action Authorized identity or denial Identity reference; role assignment Authentication mechanism, still open Application instance Protected actions fail closed Request management Create requests; apply decision rules Request details; coordinator decision Persisted request and status Requests; ownership; decision metadata Authorization; database Application instance Request operations unavailable Persistence Store authoritative records transactionally Authorized reads and writes Records; commit outcomes Requests; identities or references; notification records Managed relational database Database capacity Core workflows unavailable Notification processing Submit confirmations; retry transient failures Persisted notification intent Provider submission outcome Minimal delivery state Database; email provider Worker execution capacity Email delayed; portal status remains usable Operational controls Diagnose failures; support recovery and deletion Events; retention rules Alerts; deletion outcomes Minimal logs and control records Hosting; database; backup facilities Application and scheduled execution capacity Failures or overdue deletion may go unnoticed Notification worker and scheduled execution capabilities must be verified in the selected environment. Data Model and Lifecycle Central entities: Organization: pilot access boundary and owner of its operational records. User or identity reference: authenticated person, organization membership, and assigned role. Request: requester, necessary request details, creation time, current status, and decision metadata. Decision record: coordinator identity, decision, and time; reason only if required. Notification record: triggering event, request reference, delivery state, and retry metadata. Relationships: An organization has members and requests. Each request belongs to one requester. A coordinator decision changes a request. A persisted event can create a notification intent. Source of truth: The database is authoritative for request status. Email is a notification copy and may become stale. The spreadsheet must not remain a parallel editable authority for pilot requests. Lifecycle: Creation produces a pending request. Approval or rejection updates status transactionally. Editing, withdrawal, reopening, and deletion by users are outside the defined MVP unless explicitly approved. Delete request personal data after the agreed 90-day starting point. Account retention requires a separate policy. Notification records and logs must not preserve deleted request details. Recovery: Verify backup retention and deletion behavior before handling real personal data. After restoration, reapply overdue deletions before reopening access. Email copies are outside portal deletion control; minimize their contents and agree organizational email retention. Data and Control Flows Request creation: Member signs in through the selected authentication mechanism. Interface submits request details synchronously. Server verifies membership, ownership context, and required fields. A transaction stores the pending request and notification intent. The interface displays the committed request and pending status. Notification processing submits email asynchronously. Idempotency: Repeated submission of the same operation must not create duplicate requests. The submission identifier and its retention require definition. Coordinator decision: Coordinator opens the queue synchronously. Server verifies coordinator access. A submitted decision includes the request version being reviewed. A transaction validates the allowed status transition and version, then stores the decision and notification intent. A conflicting concurrent decision returns a conflict requiring refresh. Status viewing: Member requests their list. Server filters by authenticated ownership. Database status is displayed without depending on notification success. Error paths: Validation failure: return actionable field errors without creating a request. Database failure: do not report success. Authentication or authorization failure: deny access. Transient email failure: retry asynchronously under a defined bounded policy. Permanent email failure: retain failure state for coordinator follow-up. Ambiguous provider outcomes may produce duplicate emails; exactly-once email delivery is not guaranteed. Interface Contracts Interface Purpose and direction Authentication Data class Versioning Error behavior Responsibility Browser to application Submit requests; retrieve lists; record decisions Authenticated session; server role checks Ordinary personal data Explicit application contract Validation, denial, conflict, or temporary failure Application owner Application to identity mechanism Establish authenticated identity Mechanism-dependent; selection open Identity attributes Provider or framework dependent Fail closed on unverifiable identity Application owner and identity operator Application to database Read and persist records Restricted service identity Requests and access metadata Controlled schema migrations Transaction rollback; classified failures Application owner and database operator Notification processor to email provider Submit confirmation messages Provider-supported credentials; capability check required Recipient email; minimal status content Adapter isolates provider changes Distinguish transient, permanent, and ambiguous outcomes Application owner and email provider Operational process to storage Delete expired data; recover records Restricted operational identity Personal data and control metadata Documented policy and schema compatibility Report incomplete deletion or recovery Operational owner Open checks: Existing email provider submission mechanism, rate limits, availability, and delivery feedback. Authentication capabilities and account lifecycle. Database transaction, backup, and recovery facilities. No concrete vendor interfaces are assumed. Security and Privacy Model Assets: Request personal data, decisions, membership roles, sessions, email credentials, and backups. Trust boundaries: Browser to server. Server to database. Application to authentication mechanism. Notification processor to email provider. Operational administrators to stored records. Access principles: Members access only their own requests. Coordinators access all requests within the organization. Role assignment is restricted to an explicitly designated administrator. Database and notification identities receive only necessary permissions. Secrets remain outside browser content and application logs. Threat Entry vector Impact Existing control Additional measure Unauthorized request access Modified identifiers or list queries Disclosure of another member’s data Role and ownership requirements Server checks on every read and write; negative access tests Unauthorized decisions Member submits coordinator action Incorrect approval or rejection Coordinator-only requirement Server role enforcement; protected role assignment Session abuse Stolen session or forged action Actions under another identity Sign-in required; implementation unknown Verify secure session handling and request-forgery protection Malicious input Request fields Script execution or unsafe database operations No implementation evidence Output encoding, safe database access, field limits Sensitive free text Request description Unnecessary personal data collection No health data requirement Minimal fields; clear submission guidance Secret exposure Logs, configuration, browser bundles Email or database compromise No implementation evidence Managed secret storage; restricted access; rotation procedure Notification abuse Repeated submissions Spam and provider exhaustion Authenticated membership Duplicate prevention and measured submission controls Retention failure Backups or forgotten copies Data persists beyond policy 90-day deletion requirement Automated deletion verification and restore procedures Security review remains required; no controls have been implemented or verified in this exercise. Architectural Decisions Decision 1 — Application structure Context: small supplied pilot. Options: one modular application or independently deployed services. Decision: one modular application. Rationale: supports clear responsibilities with fewer deployment and failure dependencies. Consequences: shared deployment; modules require disciplined boundaries. Reversibility: modules can later be separated. Reevaluation trigger: measured resource contention or operational ownership needs. Decision 2 — Authoritative status Context: spreadsheet copying creates competing records. Options: portal authority or ongoing dual editing. Decision: portal authority for pilot requests. Rationale: ownership and current status require one authoritative record. Consequences: coordinators need an agreed pilot entry policy. Reversibility: data export supports return to a documented manual process. Reevaluation trigger: necessary external synchronization emerges. Decision 3 — Notification reliability Context: email may fail after a decision is stored. Options: synchronous submission or persisted asynchronous notification intent. Decision: persisted intent with asynchronous processing. Rationale: preserves decisions during provider failure. Consequences: delivery tracking and retries add limited operational work. Reversibility: email adapter is replaceable. Reevaluation trigger: environment cannot support durable processing. Decision 4 — Concurrent decisions Context: multiple coordinators may review the same request. Options: last write wins or version-checked updates. Decision: version-checked transactional updates. Rationale: prevents silent overwriting. Consequences: conflicting actions require refresh. Reversibility: policy can change with evidence. Reevaluation trigger: review workflow needs explicit assignment or locking. Decision 5 — Identity mechanism Context: sign-in is required; available identity facilities are unspecified. Options: organization identity integration or framework-supported authentication. Decision: open. Decision attempt: compare membership control, recovery, administration, privacy, operating effort, and verified capabilities. Consequences: real-user access is blocked until selected. Reversibility: retain a separate application identity reference. Reevaluation trigger: organization authentication requirements change. Decision 6 — Retention Context: deletion after 90 days is mandatory. Options: measure from creation or from final decision. Decision: open; neither interpretation is supplied. Decision attempt: obtain organizational approval for the starting point and coverage of accounts, logs, backups, and email. Consequences: retention implementation cannot be accepted yet. Reversibility: policy changes require review of already retained data. Reevaluation trigger: organizational or legal requirements change. Decision 7 — Scheduling guarantees Context: room availability rules are absent. Options: request approval only or conflict-checked booking. Decision: request approval only for the conceptual MVP. Rationale: matches supplied functions without inventing booking rules. Consequences: no automatic prevention of overlapping room use. Reversibility: scheduling rules can be added after definition. Reevaluation trigger: conflict prevention is confirmed as mandatory. Risks and Resilience Priority Risk Early indicator Prevention Reaction Residual risk High Ownership or role enforcement failure Unauthorized records appear in testing Central server authorization; access tests Restrict access; investigate exposure Implementation defects remain possible High Unclear room approval meaning Participants expect reserved availability Agree approval semantics before pilot Pause affected approvals; clarify rules Manual coordination may still fail High Retention or recovery conflict Expired records remain in backups or restored data Verify retention coverage and restore deletion Restrict restored service until cleanup External email copies remain High Database outage or loss Failed commits; failed restore verification Verify backups and recovery procedures Restore under an agreed recovery plan Recovery targets remain unknown Medium Email delay or failure Pending or failed notification intents Durable intent; bounded retries Keep portal available; coordinator follows up Duplicate or undelivered email Medium Parallel spreadsheet updates Conflicting statuses or duplicate requests Single authority for pilot records Reconcile against portal history Human workaround use Medium Unknown engineering capacity and cost No accountable build or operating owner Obtain separate capacity and cost estimates Defer implementation commitment EUR 15 pricing remains unvalidated Medium Provider dependency Unsupported integration or restrictive export Capability checks; isolated adapters Replace integration or narrow pilot Replacement effort is unknown Restart behavior: Resume pending notification work from durable records. Preserve committed requests and decisions. Reconcile ambiguous sends before retrying where provider evidence permits. Degraded operation: Email outage: request and status functions remain available; confirmation is delayed. Database outage: prevent submissions and decisions; do not display cached status as current. Identity outage: deny new unverifiable access according to the agreed session policy. MVP Scope and Development Sequence Smallest business-usable scope: One organization with controlled membership. Three responsive screens. Request creation with pending status. Coordinator approval or rejection. Member access to their own status. Agreed email confirmation events. Server authorization, decision traceability, deletion, and basic failure visibility. Postponed features and consequences: Analytics dashboard: pilot evidence must be collected separately. Payments and subscriptions: no revenue collection or price validation. Mobile app: use responsive web access. Automatic scheduling conflict detection: no availability guarantee. Spreadsheet synchronization and historical import: existing records remain outside the portal unless separately agreed. Request editing, withdrawal, and reopening: not included in current lifecycle. Dependent build order: Agree request fields, approval meaning, identity, notification events, and retention policy. Establish identity, roles, database model, and access boundaries; accept through authorization checks. Implement creation and member status viewing; accept persistence and ownership behavior. Implement coordinator decisions; accept valid transitions and concurrent conflict handling. Integrate email processing; accept failure isolation and retry behavior. Integrate retention, diagnostics, and recovery; accept deletion and restore evidence. Verify the complete three-screen journey before considering a real pilot. The EUR 120, 14-day discovery allocation and one researcher working four hours per week do not fund construction. Engineering effort, implementation cost, and operating targets remain unknown. This exercise authorizes no production changes. Verification and Handover Assumption or open requirement Verification Acceptance evidence Responsible role Status visibility is the first problem worth investigating Consent-based interviews and task observation with three volunteer participants Document uncertainty, repeat contacts, and whether participants can find current status Researcher Request approval is sufficient without scheduling enforcement Coordinator scenario review Explicit agreement on approval meaning and excluded guarantees Organization owner Role and ownership model works Authorization prototype and security review Members cannot access others’ records; members cannot decide; coordinators can review organization requests Engineering lead and security reviewer Pilot load is supportable Representative load test using supplied workload Complete workflows without lost writes; latency assessed against an agreed target Engineering lead Concurrent reviews preserve decisions Concurrency test Conflicting stale decisions are rejected; committed decision remains traceable Engineering lead Email failure does not lose requests Integration spike and fault testing Committed status remains visible; notification failure is tracked and retryable Engineering and operational owners 90-day deletion is enforceable Data sample and deletion/restore test Expired personal data is removed according to the approved policy, including after restoration Data owner and operational owner Environment is operable Provider capability checks and recovery exercise Supported integrations, designated operator, documented recovery limits Operational owner Discovery handover: Obtain consent before real interviews. Collect only necessary observations about request entry and status visibility. Treat three participants as exploratory evidence. Do not infer market demand or willingness to pay from fictional notes or a small pilot. Record the discovery decision separately from engineering funding and delivery commitments. Open decisions: Organization owner: request fields, approval rules, notification events, and retention interpretation. Engineering lead: framework, identity mechanism, integration feasibility, effort, and implementation cost. Operational owner: hosting responsibility, availability targets, recovery targets, backup behavior, and operating budget. Researcher: evidence supporting or changing the status-visibility investigation priority. Recommendation: go-with-conditions for MVP construction. The conceptual scope is coherent, but implementation commitment requires engineering capacity and funding, agreed lifecycle and retention rules, verified integration capabilities, and an accountable operator. No code, integrations, load tests, or security reviews have been completed.