Query on Designing Application Architecture

Tetos

Hi Experts.

We are trying to figure out the best possible solution architecture for a business who want to implement Navision 2009. The main business is supermarket (Convenience Stores) at fuel station operations spread across about 100 stores?

At Head Office - Nav 2009 with SQL server ENT 2008 Database.
At Sites - Nav 2009 and LS Retail 6.x with Native database and 2 POS machines.
Network - WAN using IPVPN with 64k bandwidth

The site backoffice operations include Creating and posting Sales statements, Performing Purchases and Credit Memos, Item Adjustments etc.

What is the recommended solution architecture in terms of Offline and Online back office.

Definition of Online:
1. All site users connect to the Navision server at HO through Citrix and perform backoffice operations
2. All the postings of Open statements, Purchases, Credit Memos, Adjustments will be done by site users (about 120) of them on the HO database itself.
3. Sales information at line level will be replicated from sites to HO and then posted.
4. Inventory valuation will be at HO as there is centralised inventory.


Definition of Offline
1. All backoffice operations are performed at Site Server and entries are replicated to HO. This means, Open statements, Purchases, Credit Memos, Adjustments will be done by site users at the site server and information will be replicated to HO using data director.
3. Every site is independent (not dependent on HO database) for their day to day operations.
4. However, all the data at site is being mirrored to HO and postings would be done again through batches to maintain centralised inventory.
4. Inventory valuation will be at HO

The purpose of bringing all the data to HO is to maintain central inventory, pricing, costing etc. Navision GL is maintained at HO.

Both the above models have their own Pros and Cons and we understand that a detailed analysis has to be made before conculding the approach.

We have local experts who are suggesting either of the above models. However, we want to know what is the industry practice or best practice for this kind of an environment. Are there people out there with similar installations who can share their experiences. That would be great.

Thanking you all in advance

Tetos.

stryk

Well, I'm not a retail expert, but from a general point of view, maybe some questions to consider:

In case of an ONLINE scenario
... what will be the impact of the back-office workload to the shops (e.g. blocking issues, performance, etc.)?
... what will be the impact of one shop's worload to the other shops (especially blocking/deadlocking)?
... what happens if the back-office server is shut-down? Any failover? How will the shops be able to sell?

In case of OFFLINE scenario:
... how actual/current has the shop data to be?
... how frequent could/must you replicate data?
... what is the impact of replication to the HQ (blocking, performance, etc.)?

General aspects:
... Licensing?
... Scalability?

Without really knowing, I'm guessing that the most common solution would be an OFFLINE scenario as it keeps the shops independent from each other and the HQ. I think such a solution might be more scalable; up to a point where the data replication might casue performance issues at the HQ - which might be preferable than problems with the shops.

Just my thoughts ...

Tetos

Hi Stryk. Thanks for your reply. Just to give you some inputs on your query

stryk wrote:

In case of an ONLINE scenario
... what will be the impact of the back-office workload to the shops (e.g. blocking issues, performance, etc.)?
... what will be the impact of one shop's worload to the other shops (especially blocking/deadlocking)?
... what happens if the back-office server is shut-down? Any failover? How will the shops be able to se

There will be an impact on performance in terms of Blocking and deadlocking. Im told by the partner that the table locking issues have considerably reduced with the introduction of 3 tier architecture in Nav 2009 using RTC - Is this true?
If the back office server is shut down, the shops will still continue to sell because they have native databases at each POS. We dont want business to stop at any cost. However, the back office operations by the site user would be affected.

stryk wrote:

In case of OFFLINE scenario:
... how actual/current has the shop data to be?
... how frequent could/must you replicate data?
... what is the impact of replication to the HQ (blocking, performance, etc.)?

There is no need for real time data at the HO. It is enough if the data at HO is a day old. Im not sure of the blocking / performance that could be caused by Replication.

ara3n

Hello

I have implemented both scenarios.


1st. scenario is the simpler implementation and what I recommend to customers. We have several customers that are running in this scenario.

The only time we go the second scenario is if the customer do not want the Store users to connect to HQ. For example if the stores are franchises. We have a couple of customers that run in this scenario and we have do to customization to handle all the replication request

stryk

Oh, obviously I misunderstood your definition of "ONLINE" - I was assuming you have only the HO database for all transaction, back- and front-office. But as I see now, ONLINE means actually a mixed mode beween ONLINE for back office transactions - and OFFLINE for front office transactions!
So I'd say this is the best compromise - you'll benefit from in-time transactions with the HO when necessary, but the shop transactions are performed independently. Thus, the shop business should not be affected with perfromance issues like blocking; there's only a risk with concurrent HO transactions - but this depends on how these business processes will be designed.

BTW: just the 3-tier architecture does not solve/prevent any blocking issues! With NAV blocking and dealocking is a natural problem and it depends on the workflow and business processes how your system will be affected ...

ara3n

LS does have batch posting mod that can queue the postings and NAS posts the actual entries. but yes 3 tier is not the reason to alleviate the locking.

Tetos

Thank you Rashed and Stryk.

ara3n wrote:

I have implemented both scenarios.
1st. scenario is the simpler implementation and what I recommend to customers. We have several customers that are running in this scenario

Just to broaden the discussion - We already have about 10 sites implemented on the ONLINE model and are facing a wide range of issues pertaining to locking. Everytime users are creating / posting Open Statements, Purchases, Item Journals, Calculating Statements etc, the concurrent user locking message pops up and the other users literally have to wait for a long time to continue. These issues have prompted us to re-look at the architecture and analyse the best way forward.

In your implementations - does the sales data at transactional level replicate to HO for subsequent processing? How many concurrent users connect to the HO and what kind of transactions are being performed parallely? It would be more helpful if you can throw some light on any of your similar installations. We are aware of the batch posting routine by LS and are using to post purchases.

Thanks for your info in advance.

ara3n

The statement are calculated automatically at night for previous day and posted at night automatically once reviewed by user nightly.

You could also calculate statement at store and approve them and replicate them to HQ. In HQ nightly calculate independently and post them if they agree with statement calculation of the store

LS has functionality to do the posting at store and replicate ledgers to HQ, but we do not recommend it.

Tetos

Rashed. Thanks for your reply.

Please excuse me for asking. How many concurrent users connect to the HO and what kind of transactions are being performed parallely?

The LS functionality to post statement at the stores is LS INSTORE MGMT - is that right?

Tetos

Also another query - does RTC work on Citrix environment. The idea is to have a citrix server and have all the users connect to it to access Navision rather than installing all clients.

Thanks.

ara3n

Tetos wrote:

Rashed. Thanks for your reply.

Please excuse me for asking. How many concurrent users connect to the HO and what kind of transactions are being performed parallely?

A couple of clients. They range from 50 to 300 stores.

Things that they do at HQ is receiving goods or transfer inventory.

The LS functionality to post statement at the stores is LS INSTORE MGMT - is that right?

I mentioned that they just calculate at the store. And it's the same Statement that you have at HQ. The way we implement is that everything is posted at HQ. You setup replication to replicate the statement. At HQ you run a LS job that validates the data and posts nightly. That's a modification. Your partner can help you with setting this up.

ara3n

Tetos wrote:

Also another query - does RTC work on Citrix environment. The idea is to have a citrix server and have all the users connect to it to access Navision rather than installing all clients.

Thanks.

yes RTC runs on citrix.

sehrish

Do you think it works?

ara3n

what works?