Ian Sheppard/LONDON

As early as the 1960s, computer programmers warned that using a two-digit date field was dangerous. The practice may have saved memory - which was at a premium in those early days - but, when the year rolled over to 2000, computers would act as though it were 1900.

Realisation of this has now dawned, however, at least in the developed world. In December 1997, The Gartner Group consultancy produced a compliance survey which rated countries between Levels 0 (nothing done) and 5 (all year 2000 work completed). Worldwide, only large banks had reached Level 4 (mission-critical work completed), while computer manufacturing and some other larger insurance/ financial institutions were somewhere between Level 2 (inventory complete) and Level 4, depending on the system. Aerospace fell between Level 1 (knowledge of the problem) and Level 3 (programme plan in place), which, given the safety-critical nature of the business, was a dangerously slow start.

Meanwhile, although Australia, Canada, Israel, the UK and the USA were seen to be taking the problem most seriously, at between Levels 2 and 3, the rest of the world - including Russia and China - were well behind on Levels 0 and 1, and now face a growing hurdle as their economies struggle.

Meanwhile, the USA has expressed concern at the lack of progress in France, Germany and Japan and, although it evidently rates the efforts of South Africa highly, it is not alone in its concern about air traffic control and telecommunications infrastructure in the African continent as a whole.


According to the US Department of Defense (DoD), its Y2K problems in weapon systems are being fixed during normal maintenance, while those of its automated information systems with legacy databases relying heavily on date-related calculations are consuming the majority of resources.

On a positive note, the DoD sees Y2K as "-an opportunity to eliminate unnecessary systems from the inventory". Some systems with a small "window of vulnerability" will not be used during that period, or have a temporary "workaround" solution. Where replacement is not an option and source code is unavailable, the DoD is having the code rewritten, or has a contingency plan in place.

In the civil arena, the US Federal Aviation Administration has told US Congress that it cannot guarantee a total solution, and that it has had to settle for contingency plans in some areas. Although work was to be completed by November 1999, the FAA has had to recognise that its track record for keeping big software projects on schedule is abysmal, but it remains determined to meet the non-negotiable deadline. A new FAA Federal Aviation Requirement, FAR 39.106, has been created to define and require compliance for safety-critical systems, while, outside the USA, the FAA has a Y2K International Management Team to help nations to overcome the "formidable challenges" in areas including avionics and air traffic management.


It is important to realise that the problem is not simple. For instance, it is a century-change problem, rather than something the effects of which will be known shortly after the actual date change. This means some bugs are destined to rear their ugly heads earlier or later. For example, Boeing has identified glitches for 2038, 2060 and 2090 (see this page). In addition, the date field is sometimes used to mean something different at 00, and could trigger another software routine in this case. Also, many systems have faulty date logic that does not recognise that the year 2000 is a leap year.

Aircraft manufacturers on the whole are not worried, however, and it looks as though any aircraft flying will only experience the inconvenience of problems on the ground. Boeing has found only minor problems with airborne computing, while Rolls-Royce says that engine controls have no date dependency. Services relying on dates, such as databases, are the concern, as are communications.

In the manufacturing realm of the 1990s, lean inventories, electronic data interchange and increased use of outsourcing have dramatically increased dependence upon outside suppliers and distributors. The supply chain is around the neck of even the best-prepared manufacturer, while the logistics and distribution chain is around the necks of airlines. The failure of one key member to achieve Y2K compliance for a mission critical system could cause a domino effect, disrupting the entire chain.

SAirGroup, for example, has analysed the worldwide air cargo logistics chain and information flow. With 15 or so nodes on the chain, including the airline, other airlines, forwarders, warehouses, break bulk agents and so on, 80,000 possible "relations" exist. It only takes a few key links to stumble to throw a spanner in the works.

Most companies, including R-R, have put their supply chains under the spotlight, sending out questionnaires in the first instance and then working closely with suppliers.


Embedded microprocessors are more challenging as they contain hard-coded logic for which source code is unavailable, and can be the source of erroneous date/time stamping and other corrupted information. The custom software and complex "ladder" logic is more difficult to test off-line and embedded systems are "black boxes", lacking a display or keyboard, which further complicates the remediation effort.

Industrial embedded systems also present a heightened management challenge. These systems often are not centrally or rigorously managed. Standard configuration management, software version control, documentation, database administration, and change control practices that are common in the information technology (IT) realm are often non-existent, or not rigorously enforced. Few automated tools exist to identify date-sensitive codes in embedded applications to reduce the cost of assessing code.

Time dilation is an elusive, but serious, aspect of Y2K, leading to time and date instabilities in 2000 and beyond on some microprocessors during startup, resulting in a computer or embedded system that has difficulty calculating or retaining the correct time and/or date in the year 2000 and beyond, intermittently and abruptly leaping forward (or occasionally backward) when the system is powered up or rebooted. This can lead to the failure of ports and drives, memory scrambling, or an inability to boot up.

For American Airlines and its parent, AMR, Y2K represents its largest ever information technology project. it is being carried through by the Sabre Group, of which AMR owns 80%, and has produced an inventory of 10,000 infrastructure components in 30 different programming languages, including Assembler, C, C++, Sabretalk, Cobol and PL1 - over 200 million lines of code. It includes simulators, baggage systems, alliance partners and service providers (such as fuel). Sabre asserts that contingency planning must be continuous, particularly for critical systems.

On a smaller scale, Ireland's Aer Lingus decided in early 1996 to outsource code conversion work to Alydaar, which has used automatic conversion routines. The contract was awarded after sending a sample of 25,000 lines of code out of the 2 million total to various bidders.

Industry standards decreed that this much code should take 20 man-years to convert, but Alydaar has whittled this down to 1-1.5 million lines per month per conversion team (three to five people) through automation. When corrected code batches are returned, they are frozen so that no modification is allowed. Alydaar replaces problem code with a single call to a standard date routine. On return, the code undergoes the same baseline tests as performed before despatch to ensure functionality.

The airline hoped to have the major chunk of the work, a revenue accounting system, completed by the end of July, and the rest by the end of December. Its Y2K project manager, Michael Marr, believes the problem is manageable internally, but is concerned that some are leaving things too late.

Airline reservation systems will make their first "2000" bookings in early 1999 and aircraft maintenance systems will soon be starting to book long lead-time parts, he warns.

Airlines are now irrevocably dependent on networks, particularly for computerised reservation systems. Millennium Bug experts have warned of the problems which could face network devices made before 1996, including bridges, routers, gateways, multiplexers, and E-mail servers.

"Firewall" software may mistakenly deny access to the wrong people. Network management systems may fail to collect important data. Routers and bridges might not perform the tasks they are supposed to. A huge amount of money has been spent on applications, but networks have been largely ignored.


A host of network devices built before 1996 were programmed with two-digit date fields - the same problem which affects the larger mainframe system. One industry insider is reported as saying that networks installed before 1996 have a 90% chance of experiencing a Y2K related problem. In a Y2K compliance test, some token ring networks stopped operating traffic altogether.

Many insurance companies are refusing to cover holiday companies for business liability if they are sued over Y2K problems. Passengers unhappy that their holidays have been affected by the Millennium Bug could still sue, however, because all parts of the package are the responsibility of the tour operator.

Virgin Holidays is waiting for written confirmation that its hotels can operate, while one insurer confirms that it has not given any cover to operators as none had yet demonstrated that the whole problem has been identified and resolved.

Some package providers have cancelled all holidays over the Millennium, and Thomson has yet to decide whether to take bookings over the date-change period.

Swiss company SAirGroup adopted the compliance definition as laid out by the British Standards Institute, and warns that differences between the various compliance definitions available "-may create legal problems".

Whatever happens, there seems to be a consensus that the legal profession has the most to gain from the year 2000 software bug.

Source: Flight International