Task 1.5: Determine cost optimization and visibility strategies.

• ACreate a separate organization for each business unit and move its accounts there so that each business unit receives its own monthly bill

  Incorrect

  Separate organizations split billing by account but cannot assign tagged resources in shared accounts to business units or spread the networking costs.

• BActivate the tag for cost allocation, define a business-unit cost category from accounts and tags, and add a proportional split charge for networking

  Correct

  Cost categories group costs by rules on accounts and tags, and split charge rules allocate a shared cost to other category values, for example in proportion to their costs.

• CUse AWS Resource Groups and the Tag Editor to list each business unit's tagged resources and export the resource list for finance every month

  Incorrect

  Resource Groups and the Tag Editor find and tag resources. They do not report costs or allocate shared charges.

• DTurn on consolidated billing and give finance the per-account totals from the monthly bill of the management account, grouped by business unit

  Incorrect

  Consolidated billing shows costs per account. It does not assign tagged resources in shared accounts to business units or split shared costs.

Accounts plus tags plus a shared cost to spread is exactly the combination that cost categories with split charge rules handle.

• AAttach an SCP to the subsidiary account that denies all savingsplans and Reserved Instance purchase actions

  Incorrect

  An SCP controls which API actions principals may call. It does not change how existing discounts are applied across the consolidated bill.

• BCreate a cost category for the subsidiary and exclude it from the Savings Plans utilization report

  Incorrect

  Leaving a cost category out of a report changes only what the report shows. Which accounts share discounts is set in the discount sharing preferences.

• CMove the subsidiary account to its own OU and attach a backup policy that isolates its billing

  Incorrect

  Backup policies manage AWS Backup plans. OUs and backup policies have no effect on discount sharing.

• DDeactivate discount sharing for the subsidiary account in the management account's billing preferences

  Correct

  The management account can deactivate discount sharing for individual member accounts. Discounts are shared only when both the purchasing and the receiving account have sharing activated, so the subsidiary neither gives nor receives them.

Discount sharing is a billing preference set by the management account, per member account. Access policies, reports and backup policies do not affect it.

• AUse AWS Compute Optimizer for the organization with a delegated administrator and the CloudWatch agent for memory

  Correct

  Compute Optimizer gives recommendations for these resource types across an organization, a delegated administrator can view them, and memory utilization from the CloudWatch agent improves EC2 recommendations.

• BUse the rightsizing recommendations in AWS Cost Explorer from the management account for all member accounts

  Incorrect

  Cost Explorer rightsizing recommendations cover EC2 instances only, not Auto Scaling groups, EBS volumes, Lambda functions or ECS services.

• CReview the AWS Trusted Advisor low utilization check for Amazon EC2 instances in each of the 90 accounts

  Incorrect

  The low utilization check looks at Amazon EC2 instances only, so it cannot cover Auto Scaling groups, EBS volumes, Lambda functions or ECS services.

• DTurn on Amazon S3 Storage Lens advanced metrics for the organization and export the metrics to the FinOps account

  Incorrect

  S3 Storage Lens reports on S3 storage usage and activity. It does not cover compute resources.

Rightsizing across compute types and accounts is AWS Compute Optimizer, enabled for the organization; memory needs the CloudWatch agent.

• ACreate a cost category with a team value for each team and a split charge rule that divides the cluster costs by fixed percentages

  Incorrect

  Split charges spread a shared cost across cost category values evenly, by fixed percentages or in proportion to each value's other costs. None of these methods follows the CPU and memory that each team's containers actually consumed.

• BTurn on hourly EC2 resource-level data in Cost Explorer and report the cost of each cluster instance to the teams that use it

  Incorrect

  Granular data shows the hourly cost of each EC2 instance, which is useful when an instance belongs to one owner. It cannot say how much of a shared instance each team's containers used.

• CTag every EC2 instance in the clusters with a team tag and activate that tag as a cost allocation tag for the billing reports

  Incorrect

  Cost allocation tags on resources work when a team owns whole instances, such as a dedicated node group. A shared instance carries one tag value, so its cost cannot be divided by which team's containers used it.

• DTurn on split cost allocation data for ECS and EKS, and activate the team task tags and the aws:eks:namespace tag

  Correct

  Split cost allocation data adds ECS task and Kubernetes pod line items to the CUR, priced from the amortized instance cost and the share of CPU and memory that each container consumed. ECS task tags and the generated EKS namespace tag then attribute those costs to teams.

The deciding constraints are shared instances, allocation by consumed CPU and memory, and no custom code. Split charges divide shared costs by rules that ignore container usage, and instance-level data or tags can only assign whole instances. Split cost allocation data puts container-level costs straight into the CUR, where task tags and namespace tags map them to teams.

• ARun a Savings Plans purchase analysis for the organization with a 60-day lookback and the recommended commitment

  Incorrect

  A purchase analysis examines past cost, coverage and utilization to show what spend could have been with an added commitment. AWS states that these analyses do not forecast future usage.

• BChart the EstimatedCharges billing metric of the organization in a CloudWatch dashboard and extend its trend by three months

  Incorrect

  The billing metric carries estimated charges that are sent to CloudWatch several times a day, which suits billing alarms. Extending its trend is a manual projection that comes with no prediction range.

• CExport CUR 2.0 data with AWS Data Exports and train a time series forecast on it in Amazon SageMaker Canvas

  Incorrect

  A time series model trained on exported cost data can forecast spend, but the team would build and maintain the export, the dataset and the model, which it has ruled out.

• DCreate a Cost Explorer report in the management account with a future time range of three months at monthly granularity

  Correct

  Cost Explorer forecasts are based on past usage, use data from all accounts under consolidated billing, include discounts by default and show an 80% prediction interval around the forecast, with nothing to build.

Four constraints decide it: actual past usage, every member account, discounts included and a confidence range, with no pipeline. A Savings Plans purchase analysis looks back rather than forward, a billing metric trend is a hand-made projection without a range, and a SageMaker model would need the pipeline the team refuses to run. A Cost Explorer forecast for a future time range meets every constraint and shows its 80% prediction interval on the chart.

• AThe EC2 instance quotas in Service Quotas

  Incorrect

  Quotas limit how much can be launched, not what a commitment saves.

• BSavings Plans Purchase Analyzer

  Correct

  Purchase Analyzer runs analyses with a chosen commitment, term, payment option and lookback period based on historical usage.

• CAWS Budgets with a Savings Plans utilization budget

  Incorrect

  Utilization budgets track plans already bought.

• DCost Anomaly Detection monitors

  Incorrect

  Anomaly detection watches spend for unusual changes.

Modeling candidate commitments before buying is the Purchase Analyzer.

• ATurn on Cost Explorer in each member account separately

  Incorrect

  Analysis would still be split across 25 accounts.

• BShare a custom billing view for the business unit with the lead's account

  Correct

  A custom billing view shared with an account lets its users analyze that business unit's costs in Cost Explorer without access to the management account.

• CGive the finance lead an IAM user in the management account with read-only access

  Incorrect

  This grants the management account access the company wants to avoid.

• DAWS Budgets reports emailed to the finance lead every month

  Incorrect

  Budgets reports send the performance of existing budgets to email addresses on a schedule. They do not let the lead analyze the unit's costs in Cost Explorer.

Shared custom billing views give scoped cost visibility across accounts.

• ACreate a Billing and Cost Management dashboard with widgets for each view, share it, and schedule weekly PDF delivery

  Correct

  Dashboards combine Cost Explorer, Savings Plans coverage and utilization, Budgets and detected anomalies as widgets on one page. They can be shared with accounts inside or outside the organization, and PDF reports can be emailed to stakeholders on a daily, weekly or monthly schedule.

• BConfigure an AWS Budgets report that emails the status of every budget to the CFO and the finance partners each week

  Incorrect

  Budgets reports deliver the performance of existing budgets to up to 50 email addresses on a daily, weekly or monthly cadence, which covers the weekly email, but not Savings Plans coverage, anomalies or a shared interactive page.

• CBuild a CloudWatch dashboard from the estimated charges billing metrics and share it with the finance partners' accounts

  Incorrect

  Billing metrics in CloudWatch carry estimated charges per service and in total, which suits billing alarms. They hold no Savings Plans coverage, budget status or anomaly data.

• DExport CUR 2.0 to Amazon S3, query it with Athena, and build the views in Amazon Quick Sight dashboards for the partners

  Incorrect

  Quick Sight builds business intelligence dashboards and can show any view of exported cost data, but the export, the Athena tables and the dashboards are the pipeline and the BI service that the team will not run.

The constraints are four data sources on one page, sharing outside the organization, a scheduled PDF, and nothing to build or run. Budgets reports cover only budgets, CloudWatch billing metrics cover only estimated charges, and a CUR-based Quick Sight solution needs a pipeline and a BI service. Billing and Cost Management Dashboards provide every widget, cross-account sharing and scheduled PDF delivery as part of the billing console.