Validity of notice is key to an assessment.
In Durga Ferrous P Ltd. CIT in ITA No. 672/Del/2019 dated 13 Feb 2020 the AO issued notice u/s 143(2) the very day he received the return in response to notice u/s 148. Additional ground was taken to question the validity of assessment on the basis of such notice having been issued without application of mind. The Delhi bench of ITAT quashed the reassessment citing non application of mind.
Also in the matter of writing orders the Supreme Court in Board of Trustees of Martrys Memorial Trust v. Union of India  10 SCC 734 left following three important pointers:
- Brevity in judgment writing has not lost its virtue. All long judgments or orders are not great nor are brief orders always bad;
- What is required of any judicial decision is due application of mind, clarity of reasoning and focused consideration. A slipshod consideration or cryptic order or decision without due reflection on the subject raised in a matter may render such decision unsustainable
- Hasty adjudication must be avoided. Each and every matter that comes to the court must be examined with the seriousness it deserves.