Reasoning for Duet Enterprise in addition to SAP NetWeaver Gateway

With the release of Gateway 2.0 as addition to the SAP NetWeaver stack, the question is justifiable whether this on itself is sufficient for SAP / Microsoft interoperability. Stated otherwise: ‘Do you need Duet Enterprise?’ The answer on that depends on your requirements, IT strategy, plans and situation. On level of desired application(s) functionalities as well as the Enterprise Architecture strategy, policy and plans in your company.

This blog is earlier published on SAP Community Network Blogs

Is Duet Enterprise required for SAP / Microsoft interoperability?

An answer to that question is: No, Duet Enterprise is not per se required, but it might be the wise decision. To make that decision, multiple aspects must be considered.

1. The extras Duet Enterprise brings to the table (compared to Gateway alone)
2. Your SAP / Microsoft roadmap and plans; multiple applications and a future-robust strategy, or just now for a single project?
3. Enterprise Architecture guidelines
4. Functional requirements
5. Limitations and implications of Duet Enterprise

Duet Enterprise extras to SAP Gateway for SAP / Microsoft interoperability

The extras fall into different categories.

Functional

• Standard SharePoint rendering of the imported SAP data through SharePoint Business Data webparts
• Standard CRUD+Q UI-process pattern on SAP data; for bidirectional data handling
• Support / hook into SharePoint Enterprise Search
• Collaboration workspace around SAP data entity: Customer, Product, Quote
• Integration of SAP workflow into SharePoint context
• Same for reporting: schedule + review SAP BW reports from SharePoint front-end

Connectivity

• Single Sign-On from SharePoint into SAP
• Propagation of SAP user authorizations into SharePoint roles + permissions
• Propagation of SAP data authorizations to SharePoint Search context, via construction of ACL’s on the External Data entities
• Transparant SharePoint (consumer) – SAP (provider) runtime connectivity via SharePoint BCS

Operations and lifecycle management

• End-2-end monitoring; starting from SharePoint, via SCL, upto SAP backend
• Audit trail per use case

Development

• Design tool for generation of BCS Model on basis of Gateway Model (itself generated via Gateway generation tools)
• Integration with SharePoint; Gateway is strict to provide standards-based access to SAP data, Duet Enterprise is also a first-class
  SharePoint-aware user.

Roadmap + ecosystem

• SAP and Microsoft have a roadmap outlined for Duet Enterprise
• Base functionality provided by Duet Enterprise
  product is augmented via the partner ecosystem (via Unite program)

Enterprise Architecture

The decision for Duet Enterprise implementation is not made in isolement. It must be considered and fit in the greater area of enterprise architecture. It is evident that Duet Enterprise only makes sense if your IT
landscape contains both SAP and Microsoft. But that alone is not sufficient to justify the purchase and implementation of the product Duet Enterprise. Does EA mandate usage of standards: interoperability protocols, products? And for
common-of-the-shelf products, prefer strategic suppliers Microsoft and SAP above third-party suppliers? These are just 2 examples of questions on which EA should make a thoughtful decision and statement, resulting in EA guidelines.

Functional requirements

The often required rationale for Duet Enterprise is actually a negativisme of the SAP (G)UI. So it is not so much that the decision is made for Microsoft / SharePoint, but more that it is decided against the 'detested' SAP user interface. But if the only motivation is to get rid of the SAP user interface and replace it by another, there are other possibilities. Build a custom user interface in SAP WebDynpro for instance.

Duet Enterprise starts to shine when you combine the powers of the SharePoint platform with the functionality of the SAP processing. Not merely rebuild the SAP user interface, but design and architect an improved user experience by integrating it within context of the information worker.

Limitations and implications of Duet Enterprise

Duet Enterprise is not a silver bullet for all SAP / Microsoft interoperability occassions. It has limitations, intended or as consequence of architectural desicisions. Also, implementation of Duet Enterprise has its costs.

Limitations of Duet Enterprise

• No support of REST protocol
• Limited to data-oriented, CRUD+Q service signatures
• Design-time tooling support only for inside-out approach; not for outside-in
• Full design-time tooling support only for flattened SAP data-structures
• Standard SharePoint rendering only for flattened data structures. This is actually a limitation of the standard SharePoint BCS UI controls. Rendering of complex data structures can be done via custom build SharePoint UI-controls (example: Working with complex SAP business entities in Duet Enterprise).

Costs of Duet Enterprise

The costs fall apart in different categories:

• Recurring license costs
• One-time deployment and installation effort
• Training of IT operations, architects and developers (for all: SAP and Microsoft)
• Optional (but recommended for any except a simple SAP landscape): dedicated SAP Gateway application server
• Duet Enterprise design time requires presence of SAP Enterprise Service Repository (ESR)

Conclusion

The decision for the implementation of Duet Enterprise must be made in perspective of the business requirements and middle-term enterprise architecture. If SAP / SharePoint policy is a fundamental part of the [future] business application and IT landscape, Duet Enterprise might very well be the sensible decision. Better as realizing + maintaining an own SAP / Microsoft interop layer (no matter how smart your IT people are, they will on longer term never win it from the sheer combination of SAP + Microsoft product team). And also better as purchasing + implementing third party products. That will result in more shattering in your IT landscape, while you must assure yourself of the continuity of the product and its supplier. Again here the combination SAP + Microsoft gives on the longer run more trust as that of smaller although dedicated suppliers.

Dynamic browser redirect with preserving UrlReferrer

The standard way for a dynamic redirect executed from the browser context is via 'window.location = "<runtime derived url>";'. A side effect of this approach is that you have lost the UrlReferrer information after navigation to the second page. The browser namely treats this approach the same as if the user has explicitly entered the url in the location bar. There is no referrer since referrers are about one page directly referring to another (eg. via a link), not the browser just navigating to another page. If you need the UrlReferrer setting - a typical example is for (re)directing the browser to the first page after action performed on the second page -, a simple javascript trick can be used.

<script type="text/javascript">

EditLink2 = function(a,b)
{
    var redirectLink = document.createElement('A');
    redirectLink.setAttribute("href", "<runtime derived url>");
    document.body.appendChild(redirectLink);
    redirectLink.click();
}
</script>

With this code setup, the dynamic derived redirect is added to the context of first page. As result, the UrlReferrer state is repaired and available for inquiry in the (webclient + webserver) context of second page.

User Experience improvement of OOTB SharePoint rendering of SAP data imported via Duet Enterprise

Duet Enterprise makes it simpler to bring SAP data into the realm of SharePoint based front-end. At the SharePoint side the SAP data integration is enabled via Business Connectivity Services. The SharePoint platform provides multiple standard controls that hook into BCS Service Application to render external SAP data. XsltListViewWebPart to render a view on ExternalList, BusinessDataDetailsWebPart to display details of a single external SAP BCS entity. These standard controls have a generic ui-process handling. In case the SAP process handling is different, the result may in fact be a lesser user experience as that ‘detested’ SAP UI.

However, within limitations it is possible to extend and adapt the standard SharePoint ui-process handling, while still using and relying on the standard controls.

This blog is earlier published on SAP Community Network Blogs

The standard ExternalList UI-process handling is to display all selected fields in a gridview; and display details of a selected external entity in a popup window.

In case of a relational or hierarchical data model (typical SAP structures), it is more natural to navigate to another portal page with a composite view: display some details of the selected external entity, accompanied with table based overview(s) of related items. This modified UI-process can be achieved with standard SharePoint controls by a number of measures:

1. Use javascript/jQuery to overload the standard SharePoint client-side handling that is generated for (External)List. This can be done by utilizing the standard ContentEditorWebPart for injecting the jQuery in the SharePoint page, it does not require custom server control development + deployment.
2. Modify the Xslt-rendering of the standard WebParts to beatify the rendering. Examples of this are applying conditional rendering, other display-formats of data structures, html-layout changes. Also this can be done at SharePoint configuration level, from context of the SharePoint GUI. It does not require custom server controls. Note: Xslt programming is an expertise on its own. Although you can deploy it via SharePoint GUI, it is not something that you can expect the content owner or functional administrator to do.
3. Use CSS for consistent style of the rendered data displays. Again this can be done via SharePoint GUI; no deployment required to the SharePoint farm.
4. Readible names for SAP datafields by defining readible names in the BCS resource file per SAP external contenttype. This is something to be done by the SharePoint administrator that has access to BCS Service Application UI.
5. Build a custom server control to propagate value(s) of the selected SAP external entity as filter(s) to XsltListViewPart that exposes view on ExternalList of related SAP data entity. This does require some custom SharePoint development and a farm deployment. Afterwards this generic server control can be reused in multiple SharePoint pages.
6. Build a custom server control to provide to standard BusinessDataWebPart the entity identifier of the SAP entity that was selected in XsltListViewWebPart on the referrer page. This server control implements the BCS IEntityInstanceProvider interface. This does require some custom SharePoint development and a farm deployment. Afterwards this generic server control can be reused in multiple SharePoint pages.

The effect of these measures with still usage of OOTB SharePoint controls to display SAP data imported via Duet Enterprise:

Start: browse to the SharePoint page that initiates retrieval of SAP category data (via SAP NetWeaver Gateway Model Query method) + display within XsltListViewWebpart

User clicks on one of the categories, as result the browser navigates to a second page. On that page some details of the selected category are displayed (via BusinessDataDetailsWebPart, issuing via BCS the Gateway Model Read method), and also data of 2 additional SAP entities (via Gateway Model Query method,with one or more input parameters, the value of these set as BCS filter in ReadList method.

User clicks on one the related SAP entity instance, browser navigates to a third page. On that page some details of the selected instance are displayed (via BusinessDataDetailsWebPart, issuing via BCS the Gateway Model Read method), and again also data of additional SAP entity (via Gateway Model Query method).

Conclusion

Via such SharePoint customizations the UI-process handling for external data can be largely improved. In case the User Interaction Design demands more and deeper adjustments, somewhere the line will be crossed what is sensible possible via SharePoint customization. Then it is more sensible to build custom webparts for exposing the SAP data retrieved via Duet Enterprise. For the SAP side this is transparent, as long as it can deliver the required SAP data structures to compose the SharePoint UI-handling.