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VMware Green Score in Aria Operations (formerly vRealize Operations)

Sustainability is an essential priority for every organization around the globe today. Every CxO is looking at reducing the carbon footprint in every operation and identifying processes to achieve their Green goals. Sustainability is core to VMware’s values, based on our legacy of decarbonizing digital infrastructure for our customers, value chain and operations. 

VMware helps customers significantly reduce energy costs and carbon emissions associated with a robust digital infrastructure. We also provide responsive scalability and simplified management. Refer to VMware’s Environmental Social & Governance Report 2022 for more details on how VMware products and solutions help customers decarbonise their digital infrastructure.

In VMware Aria Operations 8.6 (formerly vRealize Operations), we provided the first sustainability dashboards focused on showcasing how much carbon emissions are saved by compute virtualization and ways to optimize carbon footprint by identifying Idle workloads.

This was further enhanced with the Sustainability v2.0 story in the Aria Operations Cloud release of October 2022, which is based on three themes:

  • Identify the current Carbon Footprint
  • Track Carbon Emissions with a Green Score
  • Actionable recommendations for improving the Green score

Why Green Score?

No goal can be achieved if it is not tracked and validated against tangible target values. The same is the case with Sustainability; there should be green goals and, ideally, a “Green Score” against which an organization can work to achieve.

In reality, Sustainability covers areas beyond the scope of data centre operations. For example, a mostly empty office is not a sustainable practice as space and power are wasted. Likewise, business travel and daily commute are not green practices adding to the indirect emissions. Several factors are difficult to measure or assess, even if we consider sustainability within the data centre.

Within the data centre, we could identify the indirect emissions caused by VMware Infrastructure by measuring the electricity consumed. Based on this and the opportunities for reducing power consumption, we created a VMware Green Score computed within VMware’s circle of influence, thus providing an excellent, realistic starting point to track the decarbonization journey.

What is the VMware Green Score?

VMware Green Score is what organizations can use to track where they are in their decarbonization or sustainability journey and how they progress over time. The latter is more important than the former as it’s about “improving yourself”. The Green Score calculation includes a few assumptions, which will not impact its accuracy since we are focused not on an absolute value but on a relative scoring to help track the optimization of carbon emissions over time.

Under the sustainability dimensions of Clean Demand, Lean Operations and Green supply, in this release with the Green Score, we added five components – Workload efficiency, Utilization of physical resources, Virtualization rate, Power Source and Hardware efficiency – to compute a Green score for the organization within their data centre. To make the score easily understandable for comparing or tracking, a score between 0% and 100% is created – percentage implies a simple, linear scale.

Most metrics we use are available in Aria Operations natively or through adapters and can be used to compute Green Score. For those components not collected by Aria Operations, input values are required from the customer based on the environmental statistics and related metrics.

Calculating the VMware Green Score

By considering the five components from the data centre, the VMware Green score can be made more complete and will also provide the ability to provide actionable recommendations on specific components which need to be optimized to improve the overall Green Score.

Each component has a different weightage due to the impact each can have on the Green IT operations. Within each component, there are sub-components which are also weighted. A 100% Green Score would be the target.

Green Score components and weightage

Let us look at how each of these components is used for calculating the Green Score:

1. Workload Efficiency

Workload Efficiency measures the data centre’s waste resources and calculates a score based on various waste sources – a badge score between 0% and 100%.

Workload Efficiency (%) = Non Wastage / (Wastage + Non Wastage)

In this release, Aria Operations identifies waste resources in the environment from Idle VM, Powered Off VM, Orphaned VMDK, Snapshots and Oversized VM. These will be used to compute the total wastage.

Based on this, an environment with 100% wastage will have a zero badge score, and that with 0% wastage will have a 100% badge score.

2. Resource Utilization

This score will be based on hardware utilization from the absolute capacity without considering buffers and HA. Thus this component will be intended to drive leaner operations without impacting the SLA for operations. Following are the considerations while computing this component:

  • We consider the total capacity of physical hardware, not the usable capacity after HA and Buffer.
  • The bigger the HA and Buffer, the less lean the operations.
  • Wastage is already accounted for separately and measured against Actual Usage (not total physical capacity).

Based on this, an environment with zero usage will have a zero score, and that with 100% usage (with no buffers) will have a 100% score. A 100% score is practically impossible due to HA and buffers required in any environment; still, the badge score is important for calculating the relative values of the Green Score.

3. Virtualization Rate

Virtualization drives consolidation, thus lower power consumption and reducing the carbon footprint. So we would utilize the virtualization rate across compute, storage, network and desktop infrastructure for calculating the overall virtualization rate. Each of these virtualized platforms causes different levels of impact on reducing power consumption – Server Virtualization provides the largest power savings, followed by Storage Virtualization and Network Virtualization. Desktop Virtualization results in the least power consumption savings in the data centre since the VDI resources need to be provisioned in the data centre and client-side power consumption also needs to be considered ( although there are other indirect carbon savings with VDI, resulting from less travel to the office ).

Because of this, each virtualization sub-component is given a weighted average while calculating the badge score for the Virtualization rate, with Server Virtualization given a higher weightage and Desktop Virtualization given a lower weightage.

Aria Operations currently cannot count the physical components in the environment. Thus initial configuration inputs need to be provided as a Virtualization percentage for each sub-component in the environment to enable computing of badge score for the Virtualization rate.

4. Power Source

This component has the most significant impact on the Green Score in any environment. In this component, we are scoring based on the carbon intensity of the power source used. For, eg. traditional coal-based power sources will have a Carbon Intensity rate of 888 while Wind-based Power sources will have a carbon intensity of 26 only ( Reference: WNA Report – Comparison of Lifecycle Greenhouse Gas Emissions of Various Electricity Generation Sources )

Reference: WNA Report – Comparing Carbon Intensity for various electricity sources

Based on the above values, a 100% badge score will be assigned to a power source with zero carbon intensity (this ensures that the badge score does not go above 100% and also makes the metric future-proof), and a 0% badge score will be assigned to a power source with a carbon intensity of 1000

Normalized average values are used to calculate the score for environments with different power sources of different Carbon Intensities. The score for the entire environment will be the normalized average of all scores based on their share of power consumption.

5. Hardware Efficiency

This badge score is computed based on the fact that new generation hardware will be more energy efficient than the old generation hardware in two ways:

  • By running more workloads on the same-sized hardware
  • New-generation hardware can optimize energy consumption.

It is difficult to mathematically account for various components contributing to the environment’s hardware efficiency. Hence we have used a simplistic approach with the assumption that hardware in data centres typically lasts five years and the efficiency of new-generation hardware improves over the years. So if we give a 100% badge score for the current generation hardware, each previous year reduced by 10%, hardware five years old will have a badge score of 50%. Even though we are using assumptions here, it aligns with the fact that the VMware Green score is focused on relative scores.

Assumptions used in the VMware Green Score

Since there are several components and metrics which cannot be collected by Aria Operations or mathematically computed, there are a few assumptions used while computing the Green score:

  • Weightage assumption of components: The weightage is, by definition, subjective. The current weightage values are based on their relative importance in the overall green operations. Since the Green Score is used as a relative scoring, the actual value of assumptions does not matter in tracking the authenticity of the Green Score while tracking over a period of time.
  • Carbon Intensity of Power Source: A global average based on the industry standards for carbon intensity per power source is used in the calculations – please refer to WNA Report – Comparison of Lifecycle Greenhouse Gas Emissions of Various Electricity Generation Sources

Using the VMware Green Score in Aria Operations

As there are few inputs needed for computing the Green Score, first-time users will be prompted to configure the Green score on the sustainability home page – refer to the screenshot below:

Use the configure option to provide inputs as needed for components:

Name: The Organization name ( A new universal object added for the Green Score )

Virtualization Ratio (%) Default values are provided, which can be updated as per the environment

Power Sources (%) – The percentage of power used from each source across the environment can add eight different power sources. Default power sources are added in the page, which can be modified.

Average Age of Hardware in years (as of today) – Provide the average age of each hardware component in years.

Initial configuration for Green Score

Upon completing the initial configuration, VMware Green Score will be computed, and the Sustainability page will be updated with Green Score and the actionable recommendations from each component.

Actionable Recommendations for improving Green Score

New Metrics available for VMware Green Score

The Green Score is currently calculated at a new object – “Organization”- a universal object containing all the objects within Aria Operations. The new Sustainability metrics are currently available in this object:

Detailed information on all the sustainability metrics is available in Aria Operations Cloud documentation – Sustainability metrics

Also, you can refer to the video – VMware Aria Academy: GreenScore and Sustainability


The current VMware Green Score will allow customers to track the decarbonization goals using relative scoring. The actionable recommendation provides added value by identifying the right component to choose to optimize to improve the Green score. The new Green Score metrics can further automate actions based on the Green score.


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