SAP WM or SAP EWM - Which Is Right for My Warehouse? Q&A with SCM 2014 Speaker Mat Eames

April 17, 2014

Thanks to everyone who joined us for some in-depth discussion of EWM and SAP Warehouse Management in our online chat! SCM 2014 speaker Mat Eames of Rocket Consulting gave some detailed tips and insights on planning for WMS and your SAP systems.

Questions from readers included:

  • Will EWM be used only for complex distribution centers or will it also be used in less complex warehouses?  And is WM still supported?
  • I know that 'Queue monitoring' between ECC & SCM is a big part of EWM. How much overhead does this typically generate for a client?
  • EWM cannot report batches in bins that are nearing that true?
  • How does EWM handles inventory differences in nested handling units? Is physical counting supported with RF transaction if nested HUs are used?
  • Will EWM support Cross Docking without inbound and outbound deliveries?
  • Can EWM be integrated with PP or Transportation Management?
  • Is EWM available on HANA?
  • What functionality does EWM offer for serial number management? What about kitting?

Review the replay here or read the edited transcript below.



James Ciccone, SCM 2014: Thanks to everyone for joining us today for our chat on SAP’s warehouse management capabilities and SAP EWM.         

SCM 2014 speaker Mat Eames joins our chat today to answer your WM / EWM questions. Mat is a Supply Chain Solution Architect at Rocket Consulting and will be presenting a session on EWM and warehouse management   at our upcoming SCM 2014 conference in Nice.

Mat, thanks for joining us today – and thanks for taking our readers’ questions on this important topic!

Mat Eames, Rocket Consulting: Hi everyone, thanks for joining me today. I’m looking forward to your questions today 

James Ciccone: Great to have you here. Mat. I see lots of questions have already been submitted, so we’ll let you get started right away. We’ll try to get through as many questions in the hour as we can.   

Comment From Guest: How do you see SAP-EWM evolve in next 10 years? Will it be used only for complex distribution centers or will it also be used in general less complex warehouses?

Mat Eames:  EWM is part of the strategic roadmap that SAP has set out for supply chain execution. This means that EWM will continue to develop and expand its footprint and functionality. EWM 9.1 is coming out of ramp up and 9.2 is about to start pre-release testing. 

Functionality will only be one factor in the decision as to who implements it. Whilst it can be argued that less complex DCs don’t need all of the functionality EWM offers, you have to consider other factors in the decision. Are the requirements of your operation fixed for the next few years? Are there likely to be any factors (acquisitions or new customers) that mean you need to be able to change how you work quickly and effectively? Are you likely to need to integrate new technology into your landscape? How much does your existing WMS landscape cost to maintain and support today and tomorrow?

All these factors need to be reviewed by anyone considering changing their WMS.


Comment From Jai: Will there be any more new functionality from SAP for ERP WM?  

Comment From Mariana: Is WM going to disappear?    

Mat Eames: No, it is in maintenance mode. This means SAP will continue to support it but they have no plans to develop new functionality. SAP WM still remains a very viable option for a lot of customers.


Comment From Jason: I know that 'Queue monitoring' between ECC & SCM is a big part of EWM. This is a little concerning.
How much overhead does this typically generate for a client?

Mat Eames: Queued remote function calls (qRFCs) are used to communicate documents (deliveries, goods movements) and master data via the core interface (CIF) between ERP and EWM.

Queued data is an absolute must to be able to ensure goods movements are processed in the correct sequence.

Any overhead in terms of monitoring really depends on a number of factors. The ability of client support team to resolve the errors, how up to date the client’s SAP systems are in terms of support packs, etc. It can be time consuming in the final stages of the implementation project when the processes are configured and tested as per the requirements of the client. After the support phase the effort for monitoring the inbound/outbound queues is dramatically reduced due to the fine tuning that has been done in the earlier phases.

There are a number of automated jobs that can be set up to reprocess failed queues (due to locks or master data issues), this would then typically just leave genuine issues.


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Comment From Jai: Why are many customers NOT using TRM?  Is there any set back in using WM & TRM in place of EWM?

Mat Eames: TRM was developed to work alongside WM and adds many benefits to WM. Often it is enough for customers. The main setback is that as it is so tightly aligned to WM you have to adhere to the restrictions that go with WM. Whereas EWM was a complete rewrite from the ground up, it took some of the features from TRM and expanded them.


Comment From Sam Ranade: eWM cannot report batches in bins that are nearing that true?

Mat Eames: No, there is full SLED reporting in the Warehouse Monitor under the stock and bin node.


Comment From Neddy: Hello, It would be great if you can cover the QM interface on each WM and EWM case.

Comment From Sam Ranade: What is the roadmap for Quality Management and eWM ? It looks like there is duplication of data in ECC Inspection Plans, Sampling Plans, etc. and eWM's QIE. There is no CIF capability either. For those who have implemented QM module and now want to implement eWM, it appears that there is some master data that needs to be maintained in eWM although it exists in ECC already.

Mat Eames: The roadmap is strong; a direct integration option to ERP QM has just been released in EWM 9.1. Prior to that, QM in EWM was really designed for customers who wanted a very limited inspection process to be managed and controlled in EWM. It was never designed to replace ERP QM functionality.

With earlier releases of EWM, it is possible to connect EWM to ERP QM (or any other external QM system) if you require a more complex or full-blown quality management process. The QIE can be connected to an external QM system, such as SAP ERP QM. This way you can cover detailed analytical inspections with characteristics.

Within the activation of an inspection document in EWM, the QIE triggers the creation of an inspection lot in ERP QM. The inspection process is executed in the ERP QM system. ERP QM sends back the usage decision to the QIE after the inspection is done.

See SAP Note 1278425 – Connecting ERP QM to EWM for more information.


Comment From Dominik Tylczynski: How does EWM handle inventory differences in nested handling units? Is physical counting supported with RF transaction if nested HUs are used? That process is virtually not supported in ERP's WM/HUM.

Mat Eames: EWM can handle PI of nested HUs in the desktop transactions and via RF. You can count the top HU and the sub HUs. One restriction in RF is the sub HU can be no larger than 16 characters.


Comment From Mahesh Uppalapati: Some clients don’t have inbound and outbound delivery. They use PO to GR and GI, but they have cross-docking requirements. Will EWM support cross docking without inbound and outbound deliveries?

Mat Eames: The link documents between ERP and EWM are deliveries, and typically these are created in ERP and transferred via qRFC to EWM. However you can also use expected goods receipts which are based on purchase orders and production orders. In this case you create an inbound delivery directly in EWM.


Comment From Mahesh Uppalapati: Can we link EWM directly to PP just like WM-PP interface?

Comment From Guest: Can EWM be integrated with PP?

Mat Eames: Yes it can, there are several models that can be supported: Two EWM-managed storage locations in one warehouse; one EWM-managed storage location; MM-IM-managed storage location and two EWM-managed storage locations in two warehouses. The choice would come down to how you want to control the stock in and out of the PSA.

Comment From Tom: Does EWM cross-docking functionality work for production orders with all of the potential PP integration models you listed earlier?

Mat Eames: In theory, yes, in general all movements in and out of production are based on inbound and outbound deliveries. These are the basis for opportunistic cross docking.

There are some caveats for cross docking, such as the stock cannot be in Q status or not going through MFS.


Comment From Jason: I hear much about clients that have transitioned to EWM. However, do you have examples of clients who have gone through the comparison (WM v EWM) and have chosen to stay with WM?

Comment From Mat Eames: Yes, this is actually part of the presentation I am doing at SAP insider in Nice in May. It is not possible to discuss actual customers but we have had several that stayed with WM for different reasons.

Two examples: The first customer did not want to take an earlier release of EWM and instead built quite a highly bespoke WM/TRM solution.

The second customer wanted to use EWM, but due to the amount of warehouses they had, they could not build a strong business case to justify the licensing costs.


Comment From Mahesh Uppalapati: What are justifications to convince a customer when proposing EWM over WM?

Comment From Guest: What is the biggest advantage / selling point of EWM over WM?

Mat Eames: This would depend on a number of factors and typically you cannot view these in isolation. However, the most obvious factor is the difference in functionality, the inbuilt analytics and the ability to integrate to other systems (SAP or otherwise).

Comment From Mahesh Uppalapati: Thanks.


Comment From Guest: TM is linked to EWM through SAP ERP. Are there any plans to connect it directly to EWM? Above all, what scares me is the bunch of interfaces between TM - ERP and ERP - EWM.

Mat Eames: Yes, as of EWM 9.1 the link between TM and EWM is direct interface using enterprise services.


Comment From Guest: What are some considerations one must take when moving from a highly custom IM/WM solution to EWM?

Mat Eames: Irrespective of the level of customising in WM, one of the most important factors is the gap fit analysis. You need to understand if what you do today can be carried out on EWM. If it cannot, can it be done a different way? Before embarking on any EWM implementation you must truly understand your new world processes.


Comment From Guest: Is EWM available on HANA suite (I read somewhere that the labor management planning piece can be run on HANA)? Are there any current customers running EWM on HANA?

Mat Eames: Yes it is. Labour management is one of the areas using HANA. I cannot list customers, but happy to have a discussion at another time.


Comment From Janet: We are new to WM and in the testing mode, what advice gave you give us concerning the initial setup?

Mat Eames: Check and double check all the data. SAP has many good reports, but one thing it won't easily show you is if you have made an error on the data set up. If you go live with the errors in place, you could spend weeks chasing the error.


Comment From Maarten: With having extra possibilities for the business, extra complexity is created for IT. Documentation of, e.g., process types and or action profiles is not available or limited. How do we avoid starting too difficult, and when to start with copying 'standard' SAP to our own datasets (preventing return to standard SAP during SAP upgrades)? In short, are there best practices available?

Mat Eames: This is a common challenge for customers implementing EWM. It is so functionally rich that it can be tempting to implement everything or simply try to recreate what is typically a highly customised WM solution on EWM.

We would typically recommend a range of best practices, involving good methodology with a much higher focus on good blueprinting and suitable testing (including day of the life testing). The other key factor is scope control, as part of the blueprinting it is critical that you know what you need to implement to support your business processes and that you carry out a rigorous examination of you to be processes against the standard EWM solution trying to mold the business process to fit the EWM flows.

Obviously this is not always possible and that is where the in depth product knowledge of your consulting partner can help in finding a solution that does not hinder you in the future.

The other point to consider here is the use of Rapid Deployment Solutions (RDS). This is a method to implement a preconfigured warehousing system based on SAP Extended Warehouse Management with quickly enabled, preconfigured processes using a clearly defined scope and explicit guidance. It allows you to start now with the most important features to you, and then add functionality as you need it. The benefits (according to SAP!) are to leverage attractive, predictable-cost services and reduce your reliance on business and IT resources.


Comment From Vijay Penukonda: What functionality does EWM offer in relation to Serial Number management?

Mat Eames: Serial number management is integrated into all aspects of EWM, including product master (serial number profile assignment), EWM processes including GUI and RF, delivery processing, work centre repacking and QI, physical inventory, warehouse monitor, and integration with SAP ERP.

EWM provides three different options for serial number control:

  • Serial numbers for document items
    Serial numbers are recorded in inbound deliveries or outbound deliveries, but there is no visibility about the actual location of a serial number.
  • Serial numbers at warehouse number level
    This provides an overview of which serial numbers are available in the warehouse. In every inbound and outbound delivery you enter the serial numbers for the products for which it is required.
  • Serial numbers in inventory management
    This option stores exact storage bin information for a serial number. Every movement in the warehouse– inbound, outbound, or internally– requires the entering of the serial numbers for the products

When working with serial numbers in EWM it is possible to use multiple serial number profiles for a product. For example it could be the case that in warehouse 1 it is required to track the serial numbers of a product down to individual bin level to ensure full traceability of the product. However in warehouse 2 it is only required to capture when it arrived in the facility and when it left. In this case the default serial profile would be to capture serial numbers at bin level, but a unique record would be maintained in warehouse 2 which captured it only at warehouse level.


Comment From Guest: Can you give an overview of how closely EWM integrates with MHE (conveyance, mini-load, put systems, etc.), particularly with respect to the material flow across several of these?

Mat Eames: As of EWM 5.1 there has been the opportunity to talk directly to PLCs via EWM using the MFS component. It was initially designed to deal with quite simple conveyor systems, but has developed over time to be able to handle cranes and parcel conveyors. It uses telegrams to talk to the PLC and uses layout orientated storage control to route the product/HU on the journey from source to destination - with each relevant point on the journey being represented by a task.

Often the decision to use it comes down to two things: how much logic needs to be supported and what performance is required. The benefit with EWM is that you can have the visibility of all the movements in EWM (plus alerts) whilst leaving all the algorithms, etc., in the automation system.


Comment From Guest: Is there easy integration in SAP IS-Retail using articles instead of materials, etc.?

Mat Eames: SAP EWM supports retail as standard. There is even an RDS offering for retail.


Comment From Raj: How can I convince the customer on kitting process during inbound or outbound delivery process? How can I provide solution with handling unit creation during inbound and outbound?

Mat Eames: It is difficult to make a recommendation without further investigation or information. Kitting is used where there is generally a physical operation that needs to be tracked in terms of cost and effort. Kitting also provide you a means of telling operator what is required to build a kit for example, rather than relying on them following paper processes or having local knowledge.

So it really comes down to what is the customer trying to achieve and what information do they want to provide the operator and what information do they want the operator to capture.

EWM also offers a Kit to stock process where a new product is created, which means the ERP can see the stock holding for the kit product as well as a reverse kitting process.


Comment From Stas: Does EWM support VAS activities like bundles packaging using components backflushing based on BOM?

Mat Eames: Yes, this is called kitting. EWM supports kit to order and kit to stock as well as reverse kitting.


Comment From Doug Ogden: Does EWM work well with ECC Transportation Management or is it recommended to go also with TM?

Mat Eames: This would really depend on what you need from your transportation system. It is difficult to compare ECC TM with SCM TM in a few lines (like it is difficult to compare WM and EWM).

Essentially TM is a complete rewrite and functionality overhaul. The use of it will come down to what you need to do.

If you need a way to manage basic shipping, then ECC TM will do the job for you. If you need to perform extensive shipping functions then SCM TM is the way to go.

Both integrate very well with EWM after EWM 7.01


Comment From Brian: Our company manages their own warehouse and we are looking to use EWM for that. We also have third-party managed sites where we need to see the inventory but those sites do not perform transactions on SAP. Do you recommend a mix of EWM and IM/WM for a scenario like this?              

Mat Eames: If you need simple stock-level information for the third party’s warehouses, rather than bin level information, then I would recommend you use simple IM in the ERP, and interface from the third-party WM systems to the ERP at that level.


Comment From Olivier DARDENNE (for A&D at SAFRAN): Hello!

Question 1: In case of multi-tenant warehouses shared within different subsidiaries of the same group, but piloted through distinct SAP ERPs of the subsidiaries, what are the minimum requirements of distinct ERPs alignment to be able to pilot EWM?

Question 2: What kind of architecture would you recommend in case both international proprietary warehouses and 3PL and 4PL are to be piloted? 

Mat Eames: This is difficult to answer without knowing which release of EWM would be piloted. For example to use EWM 9.0 you need Enhancement Package 6 for SAP ERP 6.0. Once you know the release you can view the PAM for the EWM release on the marketplace

In terms of organisational structure, each plant name must be unique, i.e. you could not have plant 0001 in ERP 1, and plant 0001 in ERP 2 connected to the same EWM system (as the plant is used for the Party Entitled to dispose to separate stock ownership).

Also some consideration must be made if customer/vendors overlap, EWM does not have the same distinction between customer and vendor as ECC does, each considered as a business partner, so you cannot have customer 123, and vendor 123.

SAP note 1606493 provides best practices on selecting the right EWM deployment option.


Comment From Pankaj Dave: What is the difference between wave management in EWM and WM?

Mat Eames: Like most of the functionality in EWM it was re-written. So in EWM you can split a delivery across many waves as they are built at the delivery item level. You have the option to automatically trigger wave creation using a template. The template can control when it should be released (automatically etc.) and whether new items can be added.

In EWM 9.1 the wave can be used to create TUs and to trigger lots of onward processes (PGI etc.).  


Comment From Peter Kearns: We are scoping for a system and have a smaller DC that requires bin and batch management, is not averse to a paper system, and has processes that require picking a single article from multiple bins based on almost infinitely variable scenarios. We have EWM installed in other DCs, but this warehouse does not fit with our current config. Should we look at an EWM redesign for this location or explore WM as an option?

Mat Eames: Peter, It’s difficult to make a recommendation without further investigation, however batch management is handled much better by EWM than in WM. The suggestion would be to look at the business requirements and cost to determine whether WM or EWM is the best fit.

Consider support costs though; if you have expertise in EWM and not WM, it may favour a simple implementation in EWM over WM that could become a template for future simpler DCs in your organisation. In a template implementation, we typically find that we only have 20% localisation effort.


Comment From Doug Ogden: Are there any "How to" guidelines for creating WOCRs?

Mat Eames: I am not aware of any other than the help  and the SAP PRESS books out there. There a number of useful how to guides are here. If you have specific queries then drop me a line afterwards.

Comment From Guest: What types of resources should a project have (client and consulting partner)? From your experience, can WM resources quickly transition to EWM?

Mat Eames: This will vary tremendously depending on the size and scope of the project and the capabilities or rules of the customer.

Unfortunately it is not a quick transition from WM to EWM. But there are good tools and courses out there to accelerate this.


Comment From Najmuddin: Hi Mat, Can we have Quality inspection in EWM at the outbound stage after picking? This is because we are furniture retail where, due to storage and warehouse handling, the product could be damaged.

Mat Eames: In theory yes, you could use storage control to direct the picked stock to a work centre where the stock could be visually inspected. As of 9.1 there are new exception codes that allow you to reject stock in the work centre as not suitable for goods issue.


Comment From Dominik Tylczynski: I hear EWM can be deployed as a kind of add-on to ERP and run on the same system instance. What are the pros and cons of this approach as opposed to a decentralized landscape?

Comment From Shankar: When can we suggest an EWM Add on to ECC, as many of small and medium enterprises want the EWM functionalities in the ECC landscape?

Comment From Mahesh Uppalapati: What are advantages having SCM-EWM over add on EWM to ECC?

Mat Eames: EWM as an add-on is typically only recommended for very small warehouses where the number of delivery items and products would be low.


Comment From Doug Ogden: We understand RF is a mandatory requirement for an EWM implementation to be effective. We have some locations (e.g. temporary overflow areas), which could not easily be covered with RF. Would this be a major issue?

Mat Eames: This would really depend on the volume of transactions you want to carry out there. I would say that the ROI on full coverage would typically be good as compared to using paper and carrying out PC based updates


Comment From Dominik Tylczynski: What is the implementation effort to get EWM up and running as compared to ERP WM?

Mat Eames: By definition it is significantly higher, as typically you are talking about implementing extensive warehousing functionality and business processes as to basic warehousing functionality. The blueprinting and testing phases become more critical as you have to make sure you know what you need to build and that it works in the high performance environment of warehouse activity.


Comment From Sarka: Hello Mat. Would you recommend EWM for big production company? Is EWM able to optimize work with transfer orders (summarize them somehow to minimize necessary movements of storeman through storage or movements of shelfs in kardex shuttle)? Does it allow you to customize your own putaway / stock removal strategies without development?

Mat Eames: Difficult to make a recommendation without further investigation, but EWM has significantly better functionality to WM when it comes to work load optimisation and the ability to deal with more complex removal and putaway routines.

Comment from GB: How can MHS functionality in eWM help in Warehouse automation? Can SAP WM with help of middleware be connected to Warehouse Control System as effectively as eWM?

Mat Eames: Part of this question was answered at earlier. This really comes down to what you need from you WCS. SAP WM must be connected through some sort of middleware using IDocs. In using a middleware you are creating a ‘black box’ scenario for the automation system as you have no visibility of what is happening in WM. In WM you simply have the transfer order, but you do not know where the stock physically is in real time, this means you then have to use at least two systems to manage and report your warehouse processes. A further point to consider is that there is likely to be additional licensing and ongoing maintenance costs with the middleware option.

Comment From eyakumar: What all are the key merits of EWM over WM when it comes to a decision making while choosing a SAP Warehouse Management solution? Is it a wise decision to consider EWM though WM can fulfill the current requirements considering the future prospects?

Mat Eames: That is difficult to answer in a few lines but in general SAP say that WM covers basic warehouse processes and simple warehouse operations for small and medium-sized warehouses. Whereas EWM covers comprehensive warehouse management processes with full process transparency and flexible automated processes. It is typically for use in high performance, high volume warehouse operations in medium and large-sized warehouses.

The platform selection for your warehouse is a critical decision and you should consider all available options before making your decision. That decision has to cover a number of factors such as, company strategy today and going forward, what functionality is required, what level of customisation exists in the current solution, licensing costs, support costs, implementation costs, system landscape (interation with other systems), the roadmap of the supplier and so on.

There are lots of tools out there to help with the decision between WM and EWM, this one is offered by Rocket Consulting

Comment From Kyle_Thackwray: Hi. What benefit would a retailer get out of EWM as opposed to using SAP WM?

Mat Eames: EWM has a number of retail specific functions, such as a direct interface to AFS (apparel and footwear) and the use of catch weight. The typical deployment of EWM as decentralised is often very appealing to retailers as it offers greater stability and performance. It also offers retail specific master data such as enhanced shelf life data and trading group information. There is also retail specific SAP RDS for EWM that is a fast and predictable implementation of the most commonly used capabilities of SAP EWM for Retail customers.

You can find some additional information here:

Comment from Doug Ogden: Can you identify the common issue areas encountered during an EWM implementation (e.g. Watch out points that normally cause problems)?

Mat Eames: Not training the project team early enough, it is vital the project team get as much exposure to EWM as early as possible. It is not always practical to have customer system in place and so we offer a cloud based demo system that customers can use.

The next thing would be scope creep, EWM has so much more functionality than WM and so it is tempting for customers to want to try and implement everything or allow the scope of the project to creep.

Not enough time is invested in the blueprint phase, it is vital that all the processes are clearly documented and understood to ensure that you can make the best use of the functionality in EWM.

Typically the processes are more complex, with flexible and automated processes control. This needs to be thoroughly tested and often this is overlooked. We strongly advocate day in the life testing where you run a full day’s volume of work.

Comment From Guest: Great conversation! Thanks.

James Ciccone: Thanks everyone for joining us today, and for sticking around past 12!

We’ll be continuing this discussion live at SCM 2014 in Nice May 14-16, where Mat will be presenting his WM/EWM session as part of ourWarehouse Management track– we hope to see you there!

And thank you to Mat Eames of Rocket Consulting for taking these questions today.   Mat, I’m looking forward to seeing you in Nice! 

Mat Eames: Thanks for allowing me to take part. Hopefully I'll see some of you in Nice. You can contact me via our website or via my linked in profile . Have a good weekend!

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