Need more information. You're saying that OE and PO transactions could not be opened or posted because of a SQL locked process? And when you killed the locked process everything locked up?

Are you running day-end after each transaction?

Are you running SQL maintenance while users are in the database?

What was the process and SQL command that locked up the database?

When i killed the locked user other user became lock again.

Yes, our IC options settings is EOD during Posting.

We are running SQL maintenance at 1:30 am. Some users are not signing out Sage after working hours. sure those users are in database.

Please find the attached pictures.

If you've always had 150 users in the system and it has worked with running EOD during posting then I salute you. Unless there is a specific business reason to do so then I'd run day-end at night.

If the system has worked and now it doesn't then you have to figure out what changed.  Does the SQL server have sufficient resources? Does it need more ram, does it need to have the indexes rebuilt? What is the processor speed on that server? You indicated that you're running maintenance at 1:30 but you didn't say what you're doing. Are the maintenance tasks finished by the time that users start to access the system?

You haven't identied what the process its that it blocking the others. Was it a query that was reading from the database or updating the database?

We have some specific business reason. That is why we set the EOD during posting. 

SQL Server have sufficient resources. The processor speed is 2.10 Gz (2 Processors). We have Back up & Delete Old back up maintenance plan daily and reorganize index plan monthly. Our database is around 120 GB and users are using 24 hours (only few users are accessing after 10:30 pm). 

I didn't notice what process blocked. I am sure it was OE Transaction because majority blocked users was from OE.

We have some specific business reason. That is why we set the EOD during posting. 

SQL Server have sufficient resources. The processor speed is 2.10 Gz (2 Processors). We have Back up & Delete Old back up maintenance plan daily and reorganize index plan monthly. Our database is around 120 GB and users are using 24 hours (only few users are accessing after 10:30 pm). 

I didn't notice what process blocked. I am sure it was OE Transaction because majority blocked users was from OE.