Deployment of Patches and Operating systems is paramount for an engineer to perform the upgrade. New patches are released to fix performance issues and some other bugs. After upgrading the  Operating system, the system may have new features and increase the performance of the system.
These upgrades are so crucial, if something goes wrong it may lead to an outage situation.
Therefore, Here are some suggestions and recommendations that need to be followed prior to performing the upgrade.

They are two types of Upgrades:
1) Online Upgrades: In Online Upgrades, there is no need to take downtime to perform patching and  upgrading the operating system.
2) Offline Upgrades: In Offline upgrades, customers have to take downtime to perform patching and upgrading operating systems.

Please make sure Opening emails are sent 1 week prior to the upgrade. In opening email all the recommendations like emulex drivers and some prerequisites that need to be followed to perform the upgrade. Prerequisites may vary company to company and product to product.
While sending an opening email, If the call home is working, the Engineer can do all the pre-health checks and validate the logs. If an Engineer observes  any red alert he should inform the customer that the red alert(issue) needs to be fixed prior to the upgrade. In that scenario Deployment engineer should raise a tech support case for that issue.
This needs to be informed earlier to the customer because if you reschedule the upgrade on the day of upgrade, maybe customers have taken the downtime and a lot of approvals to perform the upgrade, that situation may cause escalation. Make sure you mention the correct time frame in the opening email to perform the upgrade.
On the day of upgrade,First thing that the Engineer should verify is the Serial number and Target version of the array. After verifying necessary details, engineers should proceed with pre health checks and follow the plan according to their product.
Each and every progress related to the system,the Engineer should give updates to the customer.
Suppose if you are upgrading SAN Primary boxes. Make sure, After each node reboot, You may verify the host paths from the customer.
Once the system is upgraded to the target version, Remote deployment engineers will proceed with post health checks and validate the host paths however, firmware should be upgraded to their expected outcome.
After completion of upgrade, Engineer may take case closure confirmation if everything seems good.
Note: While performing the upgrade, all logs must be saved.
Here are some facts that needs to be taken care while performing Upgrades:

–        Excellent customer service generates new customers and business , a great customer service reputation is a powerful differentiator in a competitive market where our customers have a lot of product/service options.

–        Excellent customer service generates return business, a happy customer is much more likely to come back and buy new products. In fact, 60% are willing to spend more on companies that provide excellent customer service.

–        Excellent customer service generates referral business – 80+% of customers will share a good experience with others.

In summary, great service is the foundation of a sustainable business. It helps increase customer acquisition and reduce customer attrition.