1. Planning.

• Assessment
  Begin by identifying which parties need access, the services they require, and the reason for their need. Document current access privileges and see if these can be reduced or exterminated. Think about using an entitlement discovery instrument for improved viewability.
• Policy formation
  Frame clear policies to grant and revoke access. Formulate guidelines on who can request permission, under which environment they can, and for what duration. Primarily for privileged roles, define time-bound rules.
• Source of truth
  Integrate your JIT access method with an Identity Provider (such as Okta, Google Workspace, Azure AD, OneLogin). It should be the authoritative reference for identities. Individual identity de/escalation rather than shared accounts offers upgraded authority control and audit precision.

2. Execution.

• Self-administered access requests
  Simplify the process by requesting access via the system and not through a person. Boost adoption rates by syncing with Instant Messaging platforms like Slack or MS Teams and making the request process detail-focused: who the requester is, the needed service, the duration of access, and the reason behind it.

• Approval process
  JIT access creates room for organizations to divide approvals among people with business context. Resource possessors and business unit supervisors often have superior context compared to IT helpdesks. Messaging platforms offer speedy responses, giving approvers the necessary information for a knowledgeable decision.

• Conditional approval workflows
  Put your constructed policies into the workflows that decide access permissions. Use an if-then format for conditions like IF Identity group "A" requests access to "B", get approval from "C", and notify "D".

• Integrations
  Consider integrating JITA with IT and security systems for added flexibility, linking with ticketing systems for automated access based on ticket status, syncing with data classification systems to modify regulations depending on data sensitivity, working with on-call schedule software for emergency approvals, and utilizing workforce training systems for access based on training completion.
• Automated provisioning and deprovisioning
  Equip yourself with a professional understanding of Google Kubernetes Engine to efficiently grant and revoke granular access within the network, decreasing reliance on people's schedules. This is vital for JIT Access as it relies on adhering to the principle of least privilege. API usage is preferable for GKE JIT Access due to their real-time capabilities and flexibility, but a diverse blend might be necessary like using SAML for authentication, SCIM for user provisioning, and API for accurate access control decisions.

3. Maintenance.

• Regular audits
  Schedule regular access log checks to ascertain that JIT access is functioning as planned. Remain vigilant for any strange patterns or activities either directly or by feeding the logs into your SIEM system.
• User training
  Train users, especially the privileged users, on the significance of the least privilege, JIT Access, and its functionalities.
• Feedback loop
  Regularly evaluate your JIT access procedures and solicit feedback from users and IT staff.

By pursuing this strategic method, you can efficiently implement an enhanced Just-in-Time access system for Google Kubernetes Engine.