Your IT landscape consists of all entities needed to run your business. Depending on the deployment model, these are systems or tenants, servers, software products, and so on.
To keep your business running and continuously improve your processes, both servers/tenants and software are changing constantly.
We can speak of three states of IT landscapes:
The landscape management process helps you, run and evolve your IT landscape providing:
The following figure shows the landscape evolution and its phases:
Figure 1: A landscape going through a change process in iterations to adapt to emerging business opportunities and new technologies.
(To see a video explaining the picture step-by-step, click the link or the figure; use the cc button to switch sub-titles on or off.)
In the picture, you see a landscape evolving from an pure on-premise to a hybrid landscape including cloud systems. The question where the landscape's layers are running, and who is responsible for which layers, is described in Deployment Models and SAP Offerings - On-Premise, Cloud, and Hybrid.
The steps to move from one state of the landscape to the next are based on the status quo to find the required changes to reach the next level. Having reached it, the cycle starts again. These iterations, are, of course, not clearly separated: Running in cycles, in the next step, the "new landscape" being planned becomes the one you use, and the next level gets into the details planning phase.
The steps shown for one cycle of planning and implementing changes are performed by different people in a company, fulfilling different roles. In this document, you'll find the roles involved and a list of key components and tools they need for their tasks.
To manage the required changes, people in different roles are involved. The main roles in landscape management are from the areas of:
So Business, IT Architecture, and Basis Administration need to work closely together in planning changes to their company's landscape to identify required changes, plan and evaluate them based on the current landscape description, and prepare the implementation of new or additional software product versions.
Figure 2: Main roles and their tasks in the process of landscape management - the big picture.
(To see a video explaining the picture step-by-step, click the figure; use the cc button to switch sub-titles on or off.)
The picture describes roles involved in the landscape management process and their tasks on the level of functional areas: Business, IT Architecture, Basis Administration, and Development.
The inner circle describes the tasks in the existing landscape, the outer circle describes the phases of planning and implementation of changes.
In the next figure, the steps in changing a landscape are shown.
In this example, the company is evolving its landscape from a pure on-premise set-up to a hybrid landscape. New options offered are identified by mapping required functions to new offerings; the plan for changes is created and implemented:
Figure 3: The functional view on planning changes - where tasks overlap, coordination is highly recommended and supported by the tools.
(For a step-by-step video explanation, click the link or the figure; use the cc button to toggle sub-titles.)
Note that this process will run the better, the better the communications between people in the different roles work. The tools you will use in planning landscape changes support communication.
In the next section, you'll get information on the entities and tools involved.
There are several tools that help in people in involved roles to perform the different steps during the planning of landscape changes. The most prominent is SAP Solution Manager, which integrates mandatory tools and provides data for the whole landscape management and related processes in SAP Solution Manager, so it's the first in the list:
For more information available at the SAP Support Portal, see Application Lifecycle Management in general; you'll find SAP Solution Manager, its Cloud Extensions, SAP Cloud ALM, Focused Solutions, and a Community link.
Figure 4: An IT landscape comprising systems of various deployment models with tools and steps of the landscape management process.
(For a step-by-step video explanation, click the link or the figure; use the cc button to toggle sub-titles.)
The picture shows a customer landscape and the tools used in landscape management. The green frame at the center shows its core functions: System Landscape Directory and SAP Solution Manager Landscape Management Database provide data for various other processes like monitoring. Also see a comparison of SAP Solution Manager, SAP Focused Run (FRUN), and SAP Cloud ALM (CALM).
The Maintenance Planner allows planning of changes for SAP systems in your landscape. Several functions have been integrated with the Maintenance Planner as utilities:
The following functions consume landscape data or Maintenance Planner output:
Left and right of the Landscape Management Process you find the main tools related to or supporting the process.
The lower part of the landscape comprises systems directly managed by the customer installed on-premise or in a private or an IaaS cloud. The upper part comprises cloud solutions (mostly) managed by the provider as managed private cloud, PaaS or SaaS cloud. These deployment models are described in the details section.
On the left-hand side of the above figure, you see the planning of a new landscape version. You can get recommendations, freely browse for innovations, and map your findings to your business needs.
The result will to a subscription to software and services and/or to planning new installations, updates, upgrades, or system conversion to be downloaded and applied to your landscape.
As described in the section on deployment models, systems or tenants of the different models are addressed with in different depth of responsibility by customers and providers. As an example, for the IaaS cloud, you will only subscribe to the infrastructure but handle the installation of systems running on-top of it yourself – that's why you find it described as being a “direct” part of your landscape. As we will see later in the section on connecting all parts of your landscape, from that perspective, the view on IaaS is different.
In this section, you will find details on the elements shown in figures 3 and 4: Deployment models, landscape entities, tools for involved roles, and services in or related to SAP Solution Manager are explained.
The sections are described as tasks and follow a "natural" sequence, leading from understanding and describing hybrid landscapes, finding new options, mapping them to your needs to define a new landscape version, getting recommendations and detailed planning and implementation of the results. The list is closing with a offering that help you manage your landscape.
The SAP Activate methodology is designed to support project teams in the new implementation, or conversion, etc. of SAP solutions on-premise or in the cloud environment. It can be used as standalone or as part of an SAP Premium Engagement:
Figure: Main phases of the SAP Activate methodology.
The methodology is structured into project phases, each containing a list of deliverables and supporting tasks. Within the project phases hierarchy project teams will be able to find accelerators like project plans, templates and examples to support their SAP implementation project.
Implementation Roadmaps for on-premise and cloud are available in the Roadmap Viewer.
More information can be found in the SAP Activate Methodology Jam group. This group has been created to guide you through the SAP implementation and delivery methodology, SAP Activate. This group provides two sub-groups for SAP Activate...
Each methodology sub-group is in its own individual Jam collaboration group that users can join according to their preference and level of access.
The following table explains the deployment models mentioned above, their purpose, names combinations and provides example of products in an SAP system landscape. Note that there are different sorts of public cloud offerings, that you can get from SAP and partners. (Just to also mention this term: Getting cloud services - even with the same deployment model and purpose - from different vendors often is called a multi-cloud approach.)
|On-Premise||Private Cloud||Public Cloud|
Pick your software
- SAP S/4HANA
- SAP ERP
Build and manage your cloud.
- Any SAP software you install and run behind your firewall
- SAP offers a similar scenario in a managed private cloud
|IaaS: Consume infrastructure as a service (network, CPU, DB, etc.); deploy SAP systems & your own software.|
- Examples offered by SAP partners: Google Cloud Platform, Amazon Web Services, Microsoft Azure, ...
|PaaS: Consume a platform as a service using services managed by SAP; build and control your own apps.|
- Offering: SAP Cloud Platform
|SaaS: Consume software as a service and benefit from operations being handled for you including provisioning, updates, and security handling.|
- Examples: SAP S/4HANA Cloud, SAP SuccessFactors
Combining any cloud offering with your on-premise systems, you will get a hybrid landscape.
Combining two or more cloud deployment models to build your landscape, you'll get a hybrid cloud.
The big difference between the various deployment model are not necessarily different technologies, but the responsibilities and level of control that you have. The following picture shows this in a generic, simplified way - concrete offerings can differ slightly from this:
Deployment models, some of their variants, and responsibilities for stack layers.
(For a step-by-step video explanation, click the link or the figure; use the cc button to switch sub-titles on or off.)
In IT-landscapes, you can find, more or less, the following deployment models and variants:
So, from a landscape management view, it is necessary to clearly state not only if you are talking on on-premise or cloud, but also, which type of cloud you use for a specific part of your landscape.
From the different levels of control that you have, you can get to the fact that the more control you need for differentiation purposes for a certain function, the more probable your choice will be an on-premise or private cloud solution. With SaaS solutions, on the other side, you get predictability of costs and benefit from managed standardized services. All options, as shown in the table above, can, of course, be combined selecting services from the SaaS cloud for standard functions and having your core functions in your private cloud, plus putting certain functions into the PaaS cloud, for example.
But note, that differentiation is also possible when consuming, for example, ERP as a service with SAP S/4HANA Cloud:
Using the PaaS services of SAP Business Technology Platform, you can develop on top of the digital core.
For more detail, see section Enhance SAP S/4HANA - SAP Cloud Platform Development & Partner Add-ons further down this page.
In the following, you will find examples for SAP products in various deployment models. For a complete list sorted by portfolio categories, see All Products.
In addition, while information for on-premise systems regarding security, availability etc. is obviously available to you. To learn about SAP's offerings in the cloud on data centers, agreements, and availability of cloud products, see the SAP Trust Center.
As we can see from the table above, there are more ways to deploy software as there have been before. The reason to choose a hybrid setup lies in the functions offered by the vendor and in the level of control need for the functions - think of specific versions you want to use or maintenance windows. These requirements, by the way, will not be the same for all areas in your whole IT landscape: While you might go for maximum control for your core applications that you use to differentiate in the market, for other applications you might want to benefit more from consuming highly standardized cloud services that helps IT concentrate on your core tasks.
Examples by deployment model:
SAP's next generation ERP SAP offering - SAP S/4HANA / SAP S/4HANA Cloud - is available in a variety of different deployment models:
For details, see blog-post SAP S/4HANA Cloud and On-Premise Deployment Options.
SAP Business One - ERP for Small Businesses
SAP Data Custodian offers a wide range of data protection features to helps you protect your data on-premise, in the cloud, and hybrid environments:
Describing your IT landscape is a prerequisite for planning changes, its maintenance and monitoring. "Managing Technical System Information" in the SAP Help Portal describes terms, which are central in landscape descriptions - technical system, product instance (version), software component (version), and product (version).
In the following you'll find a selection of blog posts that shall help you better handle you landscape data, which is a prerequisite for running business applications, systems, and Application Lifecycle Management processes alike.
Here, you find explanations, how products are maintained even if they have been installed on more than one system:
Here, you can find details about SAP software product versions, including availability and end of maintenance dates, upgrade paths, and technical release information (database platforms, Java platforms, operating systems, etc.).
Data describing your current landscape status is required to manage running processes and plan landscape changes.
The tools, what data you get, and what purpose you need to use them for, depends on the deployment models you use in your landscape.
Landscape information retrieval for various deployment models.
Following the responsibilities for the stack, landscape data are handled accordingly in customers' or vendors' tools:
To plan landscape changes on a systems level, you need data from systems that you run yourself on-premise, in a private cloud, or on top of a IaaS cloud. In addition, for monitoring of the whole landscape you need data from HEC, PaaS and SaaS as well. To learn more about the tools to gather landscape data follow the links to System Landscape Directory (SLD), and SAP Solution Manager Landscape Management Database (LMDB).
Data from SLD and LMDB is increasingly used in the SAP Support Portal, especially the Customer Profile used by the Maintenance Planner; this, however, will only work, if SLD and LMDB and/or Landscape Information Services are used and connected correctly in your landscape and to the Customer Profile - we call this their topology. To learn about the topology recommendations, read...
Verification of landscape data is an important step in having a valid landscape description, now integrated in the Maintenance Planner for landscape data in the Customer Profile. For more information see:
While SLD, LMDB, and Customer Profile focus on the systems run by your company or directly assigned to it, you can directly access information on all your systems including those you consume in the cloud - as PaaS, and SaaS - in the SAP Support Portal. For more information, see ONE Support Launchpad.
Process Management is offered by SAP Solution Manager. As of SAP Solution Manager 7.2 we regard all the systems in your landscape and all your processes your solution: This comprises processes running in your systems, SAP and non-SAP, plus manual processes.
From this point of view the solution is what you address when you improve your business processes. Use Process Management to manage your solution bringing information of business and IT architecture together. This will help you draw the new landscape version that maps new functions to landscape entities; or simply: putting the right product version to the right system: You can now model your processes graphically, and you can manage their lifecycle holistically, based on your solution documentation. You can create artifacts that are shared between multiple processes efficiently.
Process Management is divided into two parts to plan the structure of your company's solution and administrate it.
SAP Solution Manager 7.2 offers a comprehensive structure to manage your company's solution:
To accomplish this, leverage the SAP Solution Manager 7.2 process modeling capabilities to create Business Process Model and Notation (BPMN) diagrams. In addition, model the relationship between processes to better understand how your processes are interrelated.
Through new process management capabilities, you can also call for subject matter expert assistance to document a company's core business processes. For detailed information see:
This is about the solution administration part of Process Management: The system landscape comprises all your applications and systems. Systems fulfill different purposes related to the products installed, - for example SAP S/4HANA - in different roles, like development, test, production, etc. To make documenting your landscapes easier, SAP Solution Manager offers a flexible grouping mechanism called logical component groups to define the Logical System Architecture: These groups allow you to categorize systems according to their purpose and role, and to create abstraction layers that make it easier for non-technical users to link processes to systems or sets of systems.
Before implementing an SAP product, you have to decide what to use in the future, how the main components of this product will be deployed in the system landscape, how custom code or your developments can be integrated, and how the new landscape is configured.
Once you have the big picture, here you'll find the detailed information relevant for the projects to manage it:
The mentioned sources address various angles of planning. In the following, you'll find sources of information specific for the roles involved in landscape management.
Note: RISE with SAP offers a holistic on-your-terms and on-your-timeline transformation to an intelligent enterprise. You can remove complexity with a simplified engagement and guided journey through your business transformation - see:
You can get recommendations regarding new options to improve your business processes.
There are different sources available:
Before implementing an SAP product, customers have to decide how the main components of this product will be deployed in the system landscape.
Typically, now, the products have various deployment models, which result in different system landscape architectures with different characteristics. It is therefore up to you as the owner of your landscape to decide which deployment option best suits your IT and business needs.
To find recommendations and tools to plan a new landscape state - which will very probably be a hybrid one - in advance and including its integration, see:
For information on custom code handling, see the recommendations for development.
In most implementations of SAP systems, modifications exist. They need to be analyzed for being still necessary, compatibility with the new implementation, etc. For details on how-to manage custom code in conversion projects, see:
For SAP's new options for development, further down on this page, see Enhance SAP S/4HANA - SAP Cloud Platform Development & Partner Add-ons.
Usually, as a basis administrator, you will have to deal with the landscape planned mostly by business and IT Architecture; but - as discussed for the roles in landscape management at the beginning of this page -, you should be part of the discussions.
This is especially important when it comes to systems managing systems of your landscape: The topology of SLD, LMDB, and source of information on cloud systems. This is described in the following sections of this page:
There also is a series of documents to better understand the usage of SAP BW powered by SAP HANA and BW/4HANA. Furthermore, these documents deliver additional information on the implementation aspects of SAP BW on SAP HANA and SAP S/4HANA:
The first process steps that lead - bigger - changes to your landscape are those of the discovery phase. To find new options for your business, you need to browse the options available, learn about them - for very important changes, you might want to test the application in question.
Tools supporting discovery and evaluation of new functions and product versions on-premise and in the cloud.
The process steps in the discovery phase will look like this:
In SAP Roadmap Explorer, you find new options by filtering for available and planned innovations using
For more information, see SAP Roadmap Explorer.
As stated already, for cloud applications (SAP S/4HANA Cloud, SAP SuccessFactors, SAP Concur, ...) you'll find trial versions on the product's page. When it comes to on-premise, there would be considerable effort to install and configure from scratch. Instead, you can use the service of the SAP Cloud Appliance Library.
SAP Cloud Appliance Library offers a quick and easy way to consume the SAP on-premise solutions (e.g. SAP S/4HANA, SAP HANA Express Edition, SAP Data Hub, industry solutions, model companies, etc.) deployed on-top of an IaaS cloud. The CAL self-service solution offers an online library of preconfigured, ready-to-use SAP business solutions with a fully automated deployment into your own IaaS cloud account.
In most cases, new functions have to be seen in the context of the ones currently used. To learn about how to map the new functions to the existing landscape, see the next section Map New Functions and Deployment Models to Your Landscape - SAP Transformation Navigator.
To get started on your digital transformation journey, you need to map your business needs to the functions and ways to implement them offered by SAP. The SAP Transformation Navigator offers information for business (for example value drivers), and IT architecture (for example detailed information on available deployment options), plus guides for basis administration.
Mapping your current business functions to a new IT landscape can be done by freely selecting products and capabilities of interest or based on concrete information on your current landscape read from the customer profile.
For details, open the Transformation Navigator overview.
The Maintenance Planner combines functions required to plan system updates, upgrades, new installations and system conversion to SAP S/4HANA and SAP BW/4HANA. As has been discussed in the section on deployment models, this also applies to systems run in a private or IaaS cloud.
All calculations of changes affecting existing systems are based on system information mostly provided via System Landscape Directory and SAP Solution Manager Landscape Management Database.
The Maintenance Planner offers maintenance dependencies as a successor of product systems - learn about scenarios of using one or the other:
The Maintenance Planner is constantly developed adding with new functions and integration of related steps.
The following functions of SAP Solution Manager are related to landscape data or Maintenance Planner output and support your planning process:
As shown in figure 3, there are several ways to make big changes in your landscape. The following picture shows the ways to get from an on-premise Business Suite around SAP ERP 6.0 to an SAP S/4HANA-centric landscape.
Ways to get from an SAP ERP 6.0-centric landscape to an SAP S/4HANA / SAP S/4HANA Cloud-centric one.
So, as shown in the figure above, there are several deployment options on your journey to SAP S/4HANA:
For hints on how to decide a new installation vs. conversion to move to SAP S/4HANA, see the transition path.
A new installation is planed in the Maintenance Planner.
In many cases, the change of your system would include taking over data from your former system. For detailed information on the ways to handle the move to the new ERP, see
For subscription information, you need to visit the vendor's product page. For you to get an overview of the differences of the deployment models, see Deployment Models and SAP Offerings - On-Premise, Cloud, and Hybrid. Here is examples of products offered for subscription with links to the product's pages (for a complete list sorted by portfolio categories, see All Products):
There is a wide area of functions offered by SAP as software as a service - besides SAP S/4HANA Cloud, there are other functions covered by SaaS offerings:
Usually, you will use these services in addition to your ERP solution. SAP has one platform as a service offering:
While SAP does not offer infrastructure as a service as a vendor; partners solutions are available, e.g:
Managed Private Cloud:
Tools handling installation, update, upgrade, and conversion of systems and SAP HANA DB in various deployment models.
Note, that using a stack.xml file is highly recommended to keep your landscape description up-to-date.
Find out more about the tools:
In a typical landscape, you have to manage cloud systems as well as on-premise. You will find two major tasks:
While configuration of on-premise systems is well known, for many people integration with the cloud may be new but becoming increasingly important. Until today, the scenario integration of SAP Cloud solutions was based on integration guides and go through them from beginning to the end.
Connections in hybrid landscapes offered by the SAP Cloud Platform.
As shown in the figure above, the SAP Cloud Platform is a central part of the connectivity in hybrid landscapes: It handles connections that go via the Internet into your on-premise landscape.
In addition, message-based communication to other businesses, can also be handled by the SAP Cloud Platform.
For connections within the hybrid landscape, to connect systems you run on-premise to the cloud services you use, you need to install SAP Cloud Connector, As stated earlier, from a connectivity point of view, IaaS being a public cloud is working like a SaaS offering.
The Connectivity Service is always needed for the integration of Application development and integration (previously offered as SAP Cloud Platform) as part of the Business Technology Platform (SAP BTP) to other systems -on-premise or the various cloud options.
In addition, depending on your scenario, Cloud Integration Service or API Management can be used or create a pure point-to-point connection using the Connectivity Service.
Cloud Integration Automation Service provides guided work flows for selected cloud scenarios:
Invoking a work flow for a hybrid cloud integration scenario.
They make use of:
For more information, read Cloud Integration Automation Service – What is it? or watch the CIAS step-by-step video.
SAP Integration Advisor uses innovative machine learning algorithms and a centralized knowledge graph to help you simplify and streamline the implementation and adaptation of your integration process requirements for B2B, A2A, and B2G scenarios. It helps, for example, integrating multiple business partners who use different industry standards such as UN/EDIFACT, SAP IDOC and ASC X12.
SAP Integration Advisor - process and related tools.
SAP Integration Advisor makes use of APIs as well as Standards & Libraries. The use of SAP APIs is included with the subscription to SAP Integration, while other content can be purchased for a nominal monthly fee. For more information, see
The following picture shows, which tools are available for planning and implementing changes by transports:
Tools for planning and implementing changes and performing/managing transports (TR = transport request, MTA = Multi Target Archive).
As shown in the figure, for the same task, no matter in which deployment model, in most cases the same tool is used - the list focuses on systems handled by customers:
SAP Solution Manager offers tools for change management in hybrid landscapes:
SAP Solution Manager uses the Change and Transport System (CTS/CTS+) or the Transport Management Service (TMS) for content deployment. For more information, see blog-post How to use the integration of SAP Cloud Platform Transport Management into SAP Solution Manager Change Request Management and Quality Gate Management
Cloud applications can be heterogeneous. To come to a combined, working deployment, transports need to be harmonized. To achieve this, SAP introduced Multi-Target Applications (MTAs) to enable hand-over artifact between development and operation plus delivery construct for partners.
Using the development environment of SAP Cloud Platform is the recommended way to create your applications for an SAP S/4HANA backend system. In the SAP Cloud Platform Cockpit, you can:
For more information, see the SAP Help Portal on the SAP Cloud Platform Cockpit.
One very important aspect of SAP systems lies in the option to enhance functionality by partner software or custom development.
Development using the SAP Cloud Platform to enhance capabilities of on-premise, private, or public cloud functions.
Use development with the SAP Cloud Platform against another system in on-premise or cloud providing data or having other dependencies to differentiate without modifying the system you develop against.
You can set-up sub-nodes in SAP Cloud Platform development according to the tiers in your landscape. The example shows a three-tier landscape in on-premise and private cloud/IaaS.
For more information, see Explore our featured use cases for the SAP Business Technology Platform.
As a developer, you can add functionality to SAP S/4HANA as you did in SAP ERP. Here are some pieces of information:
For more information, see SAP offers Application development and integration (previously offered as SAP Cloud Platform) as part of the Business Technology Platform (SAP BTP). For details, see
Or check the SAP Extensibility Explorer:
Using the development environment of SAP BTP is the recommended way to create your applications for an SAP S/4HANA backend system. In the SAP Cloud Platform Cockpit:
For more information, see:
In the SAP Help Portal you'll find information on DevOps with SAP Cloud Platform with the following sections explaining the idea behind it, tools to be used and the relation to digital transformation:
Add-ons from 3rd-party vendors play an important role in SAP's ERP solutions for a long time. During and upgrade, it's very important to check the compatibility of add-ons and see if additional packages are needed. We find:
For details on the handling of these, see blog post List of certified ABAP Add-Ons for SAP S/4HANA and SAP Note 2861669 - List of certified ABAP Add-Ons for SAP S/4HANA, which also link to SAP Certified Solutions Directory.
* Evaluate SAP Cloud ALM for available and upcoming functions
Service Providers can monitor the customer landscapes of many products and deployment models centrally with SAP Focused Run, including SAP S/4HANA and SAP S/4HANA Cloud:
Here, you'll find more information on the ALM offerings - note that the pages also inform on Expert Wikis:
SAP Solution Manager allows to monitor systems on-premise and in the cloud. The following monitoring types are available with SAP Solution Manager 7.2:
For more information, open the SAP Solution Manager 7.2 Application Operations – Expert Portal.
SAP Landscape Management (LaMa) helps you automate repetitive tasks and gain visibility of and control over SAP and non-SAP systems in both traditional, virtual, and cloud infrastructures. In particular, LaMa provides system copy with fully automated post-copy steps. As a result, you can boost efficiency and agility and lower operating costs.
Note: After a name change the product SAP Landscape Management (LaMa) might be mixed with the topic of this page but is part of the process described here.
Use LaMa to perform activities/tasks to change your IT landscape on-premise and in the cloud:
The following figure shows an example of a task including several steps being available with LaMa:
Example of a task performed with LaMa: Automated take over of secondary HANA DB in case of an error on the primary.
As shown in the figure above, in case of a required landscape change, LaMa can be used to apply the change. LaMa executes the task/activity you picked. Even complex tasks can be automated substituting error-prone manual steps.
Tasks and activity are available with LaMa; additional tasks creation is supported.
For more information, see SAP Landscape Management.
We are working on this process in a group dedicated to Release Management and Innovation Adoption. The recommendation for the complete process is described using the example of the EHP-update of an SAP ERP 6.0 system in a Planning Landscape Changes - a Best Practice Guide.
Tools and activities involved in the best practice process of innovation adoption to update or upgrade installations of SAP Business Suite products taken from the best practices guide are describes below.
Roles, their steps and tools involved in the process of planning landscape changes taken from the best practices guide.
The example chosen for this document is a EHP update of an ERP 6.0 on-premise system. As discussed earlier, the process will be involving the tools also used for systems deployed in a private cloud or in an IaaS cloud.
This guide is reflecting the progress in process described and exist in different versions. Therefore, the links to the versions are available via an overview page: Planning Landscape Changes - a Best Practice Guide.