Comments on: Robust Design: Sandbox Principle http://www.embeddedinsights.com/channels/2010/04/05/robust-design-sandbox-principle/ Shedding Light on the Hidden World of Embedded Systems Mon, 28 Jul 2014 16:18:37 -0400 hourly 1 http://wordpress.org/?v=3.0 By: D.S. @EM http://www.embeddedinsights.com/channels/2010/04/05/robust-design-sandbox-principle/#comment-708 D.S. @EM Wed, 14 Apr 2010 18:16:02 +0000 http://robert.blogs.embeddedinsights.com/2010/04/05/robust-design-sandbox-principle/#comment-708 The sandbox is a fundamental architectural paradigm that can be used to greatly improve reliability, maintainability, testability, and portability at the expense of flexibility and possibly speed. Most often, the benefits far outweigh the costs, especially when life-cycle costs are considered. It is also a way to manage complexity in large systems. A similar concept is a closed hierarchical or layered architecture where components can only access the adjacent layers -> no direct access across multiple layers. For example, consider the TCP/IP stack, where, when correctly implemented, you can replace any number of layers and still have correct operation. And the developer of the new layers needs only to consider the adjacent layers ... no hunting through a huge code base to find and consider every usage! Strong encapsulation is always a good idea, regardless of the language or hardware architecture. If it looks like spaghetti on a UML diagram, think again! The sandbox is a fundamental architectural paradigm that can be used to greatly improve reliability, maintainability, testability, and portability at the expense of flexibility and possibly speed. Most often, the benefits far outweigh the costs, especially when life-cycle costs are considered. It is also a way to manage complexity in large systems.

A similar concept is a closed hierarchical or layered architecture where components can only access the adjacent layers -> no direct access across multiple layers. For example, consider the TCP/IP stack, where, when correctly implemented, you can replace any number of layers and still have correct operation. And the developer of the new layers needs only to consider the adjacent layers … no hunting through a huge code base to find and consider every usage!

Strong encapsulation is always a good idea, regardless of the language or hardware architecture. If it looks like spaghetti on a UML diagram, think again!

]]> By: D.H. @LI http://www.embeddedinsights.com/channels/2010/04/05/robust-design-sandbox-principle/#comment-706 D.H. @LI Tue, 13 Apr 2010 14:28:23 +0000 http://robert.blogs.embeddedinsights.com/2010/04/05/robust-design-sandbox-principle/#comment-706 <p>Products are a compromise. Yes, a screwdriver tends to be a very reliable but limited and simple tool, yet, in order to cope with this simplicity I end up lugging a tool box of such simple things around. If I could opt for a 'Dr Who sonic screwdriver' that can undo anything and everything and drop neatly into my pocket.... </p> <p>Who knows, the point is that yes, a simple product is easier to make and can be more robust, a more complex product though gives its user more... theres room for both approaches.</p> Products are a compromise. Yes, a screwdriver tends to be a very reliable but limited and simple tool, yet, in order to cope with this simplicity I end up lugging a tool box of such simple things around. If I could opt for a ‘Dr Who sonic screwdriver’ that can undo anything and everything and drop neatly into my pocket….

Who knows, the point is that yes, a simple product is easier to make and can be more robust, a more complex product though gives its user more… theres room for both approaches.

]]> By: W.K. @EM http://www.embeddedinsights.com/channels/2010/04/05/robust-design-sandbox-principle/#comment-707 W.K. @EM Thu, 08 Apr 2010 17:30:36 +0000 http://robert.blogs.embeddedinsights.com/2010/04/05/robust-design-sandbox-principle/#comment-707 <p>You are correct in that windows offers a few more possible actions than the Mac OS. BUT windows is grossly inferior to any of the DOS operating systems as far as offering the ability to do things other than what somebody else decides is all that I need to do. It really is similar to the concept, in the book "1984", where the language was redesigned to avoid "badthink". The windows OS is similar in that it has chosen to allow choices in truly worthless areas like wallpaper and screen savers and icons, while assuring that the files that we create are all stored in an area called "my documents, assuring that any hacker who wishes to do damage, or hold them hostage, is aware of exactly where they are located. Likewise, anybody who breaks into my computer knows exactly where to look to find my personal files. </p> <p>So tell me this: how has limiting my options improved this product. </p> <p>So it is true that by limiting the ability of a product to do things, it is indeed possible to create a product that can only do one thing adequately.</p> You are correct in that windows offers a few more possible actions than the Mac OS. BUT windows is grossly inferior to any of the DOS operating systems as far as offering the ability to do things other than what somebody else decides is all that I need to do. It really is similar to the concept, in the book “1984″, where the language was redesigned to avoid “badthink”. The windows OS is similar in that it has chosen to allow choices in truly worthless areas like wallpaper and screen savers and icons, while assuring that the files that we create are all stored in an area called “my documents, assuring that any hacker who wishes to do damage, or hold them hostage, is aware of exactly where they are located. Likewise, anybody who breaks into my computer knows exactly where to look to find my personal files.

So tell me this: how has limiting my options improved this product.

So it is true that by limiting the ability of a product to do things, it is indeed possible to create a product that can only do one thing adequately.

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