companion document for "The "Real" Y2K Problem - Is it Embedded Systems or is it Software?" : LUSENET : TimeBomb 2000 (Y2000) : One Thread

Fair use : Education and Research only

I am posting this as a companion document for the thread below;

 The "Real" Y2K Problem - Is it Embedded Systems or is it Software?

Strategic Analysis Report 
16 August 1999
Year 2000 World Status, 2Q99: The Final Countdown
L. Marcoccio, J. Duggan, M. Hotle, A. Kyte, D. Vecchio, A. Di Maio

 5.0 Embedded-System Failure Rates

From the link

 Year 2000 World Status, 2Q99: The Final Countdown


We present our final assessment of progress toward year 2000
readiness, covering enterprises from many different industry sectors
and geographies. During the two years that we have been performing
this survey activity, we have seen many respondents move from naivete
and denial to realization and self-promotion. Fortunately, we have been
able to make full use of GartnerGroup's extensive research network 
vendors, clients and associates  to enable us to make a broad and
comprehensive assessment of the true state of progress.

5.0     Embedded-System Failure Rates

Return to TOC

There are distinct and separate year 2000 problems for information systems and embedded systems. Information systems' problems affected the vast majority of business applications and required that significant percentages of code be remediated or replaced. It is easy to understand why information systems process dates, and therefore why they might have problems. Furthermore, IS problems have already started: they will happen over an extended period of time.

The contrast with embedded systems is marked. Year 2000 problems only affect a small percentage of embedded systems. Many people find it difficult to understand why embedded systems process dates, and therefore why they can be vulnerable. Also, embedded systems' problems have not started occurring in any statistically significant numbers: since embedded systems are largely "real-time" systems, those that do have problems are most likely to experience them at or around midnight on 31 December 1999.

In nearly every enterprise, year 2000 awareness and action start with information systems. This tends to lead to a position where the business believes that the IS department is responsible for year 2000 in general. However, IS staff have very little previous experience of real-time control systems, and, where IS staff have been given responsibility for running embedded-system activities, the projects almost inevitably stall. To emphasize that IS staff are unlikely to be able to make a substantial contribution to the embedded-system project, GartnerGroup defines an embedded system as "any electronic system not acquired with the IS budget."

5.1     Real-Time Clocks

Return to TOC

Although there are many different types of electronic devices that can be considered embedded systems, one common feature links all the embedded systems that suffer from year 2000 problems: they must have access to a persistent source of date information. This is almost universally supplied by a real-time clock (RTC). An RTC is a device that uses a battery to oscillate a crystal and then counts the oscillations to maintain time and date. An embedded system may have its own RTC, or it may have access to date information by virtue of being network connected to another device that itself has an RTC. Any device that does not have an RTC and is not connected to another device is incapable of suffering a year 2000 failure.

Most RTCs provide a two-digit year. This is in itself not a problem. The function of the RTC is to supply date and time information, but in order for useful work to be done the information must be interpreted by a program. A program may read a two-digit year and quite correctly interpret "00" as "2000." Equally, a program reading a four-digit year may choose only to access the last two digits and misinterpret "00" as "1900." The key point to note is that there is nothing inherently wrong with RTCs that only provide two-digit year data.

5.2     Microcontrollers

Return to TOC

The most numerous ES devices are microcontrollers. The particular characteristic of these devices is that they are not programmable: the program is burnt onto the chip at the point of manufacture. While there are billions of these devices in existence, they are very simple devices and are generally not capable of processing complex data like date and time. When people say that there are "chips" in domestic appliances like coffee machines, toasters and irons, what they actually mean is that there are microcontrollers in some of these machines. They are not at risk of year 2000 failures. Based on information received from many clients who have undertaken extensive research in this area, we believe that, at the century boundary, free-standing microcontrollers will experience a year 2000 failure rate of less than one in 100,000 (0.8 probability).

5.3     Microprocessors

Return to TOC

Whereas microcontrollers are pre-programmed devices, microprocessors are considerably more complex. These are effectively "computers on a chip": they provide the ability to execute instructions contained in a program that comes from somewhere else. Therefore, microprocessors are neither compliant nor noncompliant: they are passive devices that need a program in order to become active. The typical configuration for a microprocessor is as the heart of a programmable logic controller (PLC). The program the microprocessor will execute will typically be found on a co-mounted chip such as a programmable read-only memory (PROM). It is the program that must be assayed for year 2000 compliance, not the microprocessor.

A PLC with no RTC and no connection to any other device with an RTC cannot generate a date from thin air and should be considered to have the same potential for year 2000 problems as a microcontroller: one in 100,000.

A PLC with no RTC but that is connected to another device (typically a PC) that does have an RTC and that can therefore theoretically pass date information to the PLC in a network message is slightly vulnerable to year 2000 anomalous processing. Information garnered from many clients suggests that, although it is unusual, some such devices can have problems. The numbers are small: through 2001, fewer than 0.25 percent of microprocessors not co-mounted with RTCs will demonstrate year 2000 anomalous processing (0.8 probability).

We use the term "anomalous processing" advisedly. It simply means that some function or process that should be supported by the device will not be supported in the expected manner. This is very different from "fail." A great many problems with embedded systems are cosmetic or minor in nature. For example, a PLC may be connected to a pressure sensor, and one of its functions may be to open a valve if the pressure reaches a certain threshold. A secondary function could be to write an audit record of the event, where the audit record has date and time as part of the information. If such a PLC has a year 2000 problem, it may well still open the valve under the correct conditions but write the date information in an incorrect format. The device is noncompliant, but it is questionable whether it has "failed." To make such a judgment, it would be necessary to discover the ramifications of the incorrect date format in the audit record.

The question inevitably arises: Why would a microprocessor process dates? The most common date-processing function in real-time control systems is "interval timing"  that is, calculating the interval in time between two events. For instance, a train goes through a set of points at Time A. Another train goes through a set of points at Time B. The PLC has to make a decision based on the time interval between the two events  e.g., if less than 20 minutes, perform Action X; otherwise, perform Action Y. There are many ways of programming this function. Where an RTC is available, the time of Event A could be captured and stored in a register, so that the time of Event B can be captured and the calculation made. Because nearly all RTCs support date as well as time, the programmer may store date and time in the registers.

Why is this of particular interest when considering year 2000 problems in PLCs? Because GartnerGroup has identified that many of the year 2000 problems in interval-timing algorithms can only ever occur if the first event (Event A) occurs in "99" and the second event (Event B) occurs in "00." We call this type of problem "transient noncompliance," because, although the PLC program may be noncompliant, the noncompliance can only happen once. In such cases, if the system is inactive at midnight  i.e., there is no Event A with a "99" date waiting for an Event B  the noncompliance will not be activated and the algorithm will function satisfactorily for another 99 years. Transient noncompliance is the most common form of noncompliance in microprocessor devices: at least 7 percent of microprocessors co-mounted with RTCs will demonstrate transient year 2000 anomalous processing at the century boundary (0.7 probability).

It is important to note that there are many other miscellaneous reasons why microprocessors can suffer year 2000 problems. Some of these problems will be persistent. However, our research shows that, through 2001, fewer than 2 percent of microprocessors co-mounted with RTCs will demonstrate persistent year 2000 anomalous processing (0.8 probability).

5.4     Large-Scale Embedded Systems

Return to TOC

While microcontrollers and microprocessors correspond to the conventional view of embedded systems as "chips," large-scale embedded systems (LSESs) generally look like much more traditional computers. LSESs are typically PCs or other dedicated computers with traditional configurations involving screens, keyboards, processors and disks. The family of LSESs incorporates supervisory control and data acquisition (SCADA) systems on the factory floor, distributed control systems (DCSs) at the heart of process control, and building management systems (BMSs) controlling heating, ventilation and air conditioning, lighting and security access systems in commercial property.

These systems are typically the hub of a network of lower-level devices, such as PLCs. Since they are based on conventional information systems architecture, with an operating system loaded from disk, with multiple programs that can also be loaded from disk, and complex data stores on disk, they have considerably greater complexity than the two other main families of embedded systems, microcontrollers and microprocessors. All LSESs are date sensitive. Our research shows that, through 2001, at least 35 percent of LSESs will demonstrate anomalous date processing (0.8 probability).

5.5     Embedded-System Comparative Failure Rates

Return to TOC

The decomposition of the embedded-systems problem into the three families  microcontrollers, microprocessors and LSESs  shows the futility of attempting to provide a percentage failure rate for embedded systems as a whole. There are tens of billions of microcontrollers, but only tens of millions of microprocessors and only millions of LSESs.

Figure 12 illustrates some of the essential differences between the three families of devices.

Source: GartnerGroup

Figure 12. Differences Between Microcontrollers, Microprocessors and LSESs

Return to TOC


-- Brian (, August 29, 1999


Unfortunately I blew the graphics so you will have to go to the site and check them out. Recommended

-- Brian (, August 29, 1999.

Aloha Brian: Everyone else probably already knows the answer to this question, but I don't soooo... just who is the Gartner Group? Who initially engaged them? Why do they do these studies? I mean, is it simply because they like it or are they in someone's employ? Sorry if this is an incredibly stupid question (after all, I have been reading their reports for some time now), but really, I don't know. Aloha.

-- grngrl (, August 29, 1999.


Good question! Also I am from Vancouver Island so we are Islanders :o) (assuming you are from Hawaii)

Lou Marcoccio has been a consistant witness during testimony for the Gov.Reps. of the US of A. The GartnerGroup remediate software for a profit so they have a bias but they are amoung the first to provide solutions.

Like it or not they are a measure of Y2K, here is the link for the senate Y2K web site for testimony. This is where you will find their Y2K documents. The site is down right now or I would point out some documents.

Senate Y2K Committee

-- Brian (, August 29, 1999.


Qoute from the last testimony

 Hearing Statements before the US Senate, Special Committee on Year 2000 Technology Problem (unofficial record)

Hearing: International Year 2000 Issues:

Will the World Be Ready?

Opening Statement

Lou Marcoccio

Research Director, Gartner Group


Gartner Group is a worldwide business and information technology advisory company, providing research and advice in more than eighty major focus areas of business and technology. One of those focus areas is Year 2000. Gartner Group researches Year 2000 status, issues, and best strategies, and provides advice and methods to companies and governments throughout the world. We are commonly referred to as the best Year 2000 experts and the company with the most accurate and realistic understanding of Year 2000 progress and status worldwide.

-- Brian (, August 29, 1999.

Thanks for posting the Gartner Group information and the link, Brian. This is good background for embedded systems discussions.


-- FactFinder (, August 29, 1999.

...and only MILLIONS of LSES (Large Scale Embedded Systems)...ALL of which are DATE SENSITIVE!!

As I wrote last week, if you talk to Cory, it is large scale enterprise systems...If you talk to the Plutonium Recovery Plant, it is process control embedded systems, whish MUST use dates for DATA LOGGING purposes (historically the reason Digital systems ever were allowed into the Sanctum Sanctorum of REAL TIME process control.)

Face it folks, every one of these people are correct. These DIGITAL SELF DESTRUCT DEVICES ARE EVERYWHERE!!

-- K. Stevens (kstevens@ It's ALL going away in, August 29, 1999.

Moderation questions? read the FAQ